Focus On Science Grade 7 (Teacher's Guide)

FOCUS-ON TEACHER’S GUIDE SCIENCE 7 Active-learning approach Contextual learning 21st Century Learning Skills Hands-on activities Constructivist approach Consulting author Giam Kah How ©Praxis Publishing_Focus On Science

CONTENTS Introduction iii Developing an Understanding of Scientific Concepts and Theories iii Developing Scientific and Thinking Skills vi • Inquiry-based Learning vi • Constructivism vii • Contextual Learning vii • Higher-Order Thinking Skills (HOTS) vii • 21st Century Skills viii • STEM/Projects ix Developing Scientific Attitudes and Noble Values ix How to Use the Focus-on Science Series xi Scoring Rubric for Affective Domain xiii Scoring Rubric for Scientific Thinking xiv Scoring Rubric for STEM Activities/Projects xv Scheme of Work xvi Science and Measurements 1 Lesson 1.1 What is Science? 2 Lesson 1.2 Science Laboratory 4 Lesson 1.3 Measurements 7 Lesson 1.4 Measuring Tools 10 Matter 18 Lesson 2.1 States of Matter 19 Lesson 2.2 Physical and Chemical Changes 25 Lesson 2.3 Density 28 Temperature and Heat 34 Lesson 3.1 Temperature and Scale 35 Lesson 3.2 Thermometers 37 Lesson 3.3 Expansion and Contraction of Matter 40 Lesson 3.4 Heat Capacity 44 Lesson 3.5 Heat Transfer 47 Lesson 3.6 Heat Conductors and Heat Insulators 51 Lesson 3.7 How Types of Surfaces Affect Heat Absorption and Emission 53 Lesson 3.8 Body Temperature Regulation 56 Motion and Force 61 Lesson 4.1 Motion 62 Lesson 4.2 Force and Motion 66 CHAPTER 1 CHAPTER 2 CHAPTER 3 CHAPTER 4 Teacher’s Guide Focus-on Science Grade 7 i © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Living Things 73 Lesson 5.1 Biodiversity 74 Lesson 5.2 Living and Non-living Things 76 Lesson 5.3 Classification of Living Things 79 Interactions Among Organisms and the Enviroment 86 Lesson 6.1 Biotic and Abiotic Components 87 Lesson 6.2 Food Chains and Food Webs 90 Lesson 6.3 Nutrient Cycles in an Ecosystem 93 Lesson 6.4 Interactions between Organisms 95 Lesson 6.5 Factors that Affect the Organisms and Environment 98 Earth and the Solar System 104 Lesson 7.1 The Solar System 105 Lesson 7.2 Earth and Its Satellite 108 Lesson 7.3 The Sun 111 CHAPTER 5 CHAPTER 6 CHAPTER 7 Teacher’s Guide Focus-on Science Grade 7 ii © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Introduction The Focus-on Science Series is designed to support the teaching of science in lower secondary schools by making science learning more engaging for students. The theoretical framework of this series is based on the understanding that science is a body of knowledge and skills that provides an understanding of nature. It is also to nurture curiosity and creativity. This series aims to support the learning of science by focusing on three main objectives: 1. Developing an understanding of scientific concepts and theories 2. Developing scientific and thinking skills 3. Developing scientific attitudes and noble values Developing an Understanding of Scientific Concepts and Theories Scientists have been collecting data, facts and ideas for centuries. From the data, scientists have formulated concepts, principles and theories. This knowledge of science is the product of science. The content in this series sets out the scientific knowledge, facts and ideas that students need to understand. The contents of the series are written to ensure students are able to achieve all the learning goals outlined in the lower secondary science curriculum as follows. At the end of phase D: 1. Students can classify living things and objects based on their observed characteristics, identify the properties and characteristics of substances, differentiate between physical and chemical changes, and separate simple mixtures. 2. Students can describe atoms and compounds as the smallest units of matter, and cells as the smallest units that make up living things. They can identify the organisation of living things and analyse the connections between organ systems and their functions, including abnormalities or disorders that may occur in specific organ systems, such as digestive system, circulatory system, respiratory system and reproductive system. They can also explain the interactions between living things and their environment, develop strategies to prevent and mitigate pollution and address issues related to climate change. Additionally, they are encouraged to explore the concept of inheritance and learn about the practical applications of biotechnology in everyday life. 3. Students are able to measure various physical quantities they encounter and explore different types of motion and forces. They develop an understanding of the relationship between work and energy, measure temperature changes caused by transfer of heat energy, and differentiate between insulators and conductors of heat. 4. Students have a clear understanding of motion, force and pressure, including basic principles of simple machines. They also comprehend vibrations and waves, as well as the characteristics of light, such as reflection and refraction. Furthermore, they are familiar with simple optical tools commonly used in daily life. 5. Students can construct basic electrical circuits and understand the relationship between magnetism and electricity. They can apply this knowledge to solve everyday challenges and problems. Teacher’s Guide Focus-on Science Grade 7 iii © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

6. Students can explain the relative position of the Earth-Moon-Sun in the Solar System and comprehend the structure of the Earth’s layers. This knowledge enables them to understand deeper natural phenomena and play their roles in disaster mitigation. 7. Students recognise pH as a measure of substance acidity or alkalinity, and utilise it to classify materials based on their pH as acids or bases. With this understanding, students identify the physical and chemical properties of soil and their relationship to organisms and environmental conservation. 8. Students demonstrate the determination to make decisions and avoid harmful additives and addictive substances that can negatively impact both themselves and the environment. Each grade contains a specified and detailed list of lessons based on the learning goals outlined in phase D. Grade 7 Grade 8 Grade 9 Chapter 1 Science and Measurements 1.1 What is Science? 1.2 Science Laboratory 1.3 Measurements 1.4 Measuring Tools Chapter 1 Introduction to Cells 1.1 Cells and Microscopes 1.2 Animal and Plant Cells 1.3 Unicellular and Multicellular Organisms, and Cell Specialisation Chapter 1 Human Reproductive System 1.1 Cell Division 1.2 Human Reproductive System 1.3 Puberty 1.4 Menstrual Cycle 1.5 Fertilisation 1.6 Pregnancy 1.7 Common Disorders and Diseases of the Male and Female Reproductive Systems 1.8 Lifestyle Factors that Support the Reproductive System Chapter 2 Matter 2.1 States of Matter 2.2 Physical and Chemical Changes 2.3 Density Chapter 2 Structures and Functions of the Human Body Systems 2.1 Food and Digestive System 2.2 Circulatory System 2.3 Respiratory System 2.4 Excretory System Chapter 2 Reproduction in Animals and Plants 2.1 Sexual Reproduction in Animals 2.2 Asexual Reproduction in Animals 2.3 Sexual Reproduction in Flowering Plants 2.4 Pollination 2.5 The Development of Fruits and Seeds in Plants 2.6 Seed Dispersal 2.7 Germination of Seeds 2.8 Reproduction of Ferns, Mosses and Conifers 2.9 Asexual Reproduction in Plants 2.10 The Use of Reproductive Technologies Teacher’s Guide Focus-on Science Grade 7 iv © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Grade 7 Grade 8 Grade 9 Chapter 3 Temperature and Heat 3.1 Temperature and Scale 3.2 Thermometers 3.3 Expansion and Contraction of Matter 3.4 Heat Capacity 3.5 Heat Transfer 3.6 Heat Conductors and Heat Insulators 3.7 How Types of Surfaces Affect Heat Absorption and Emission 3.8 Body Temperature Regulation Chapter 3 Work, Energy and Simple Machines 3.1 Work 3.2 Power 3.3 Sources and Forms of Energy 3.4 Simple Machines Chapter 3 Inheritance 3.1 Genetic Material 3.2 Inheritance of Traits 3.3 Laws of Inheritance 3.4 Inheritance in Humans 3.5 Genetic Disorders 3.6 Selective Breeding 3.7 Adaptations and Natural Selection Chapter 4 Motion and Force 4.1 Motion 4.2 Force and Motion Chapter 4 Vibrations, Waves and Light 4.1 Vibrations 4.2 Waves 4.3 Light and Optical Instruments Chapter 4 Biotechnology 4.1 What is Biotechnology? 4.2 Applications of Biotechnology and its Importance Chapter 5 Living Things 5.1 Biodiversity 5.2 Living and Non-living Things 5.3 Classification of Living Things Chapter 5 Elements, Compounds and Mixtures 5.1 Atoms and Molecules 5.2 Elements 5.3 Compounds 5.4 Mixtures Chapter 5 Electricity 5.1 Electric Field and Electric Potential Difference 5.2 Electric Circuits 5.3 Electric Current, Potential Difference and Resistance 5.4 Series and Parallel Circuits 5.5 Electrical Energy and Electrical Power 5.6 Using Electricity Safely at Home Chapter 6 Interactions Among Organisms and the Environment 6.1 Biotic and Abiotic Components 6.2 Food Chains and Food Webs 6.3 Nutrient Cycles in an Ecosystem 6.4 Interactions between Organisms 6.5 Factors that Affect the Organisms and Environment Chapter 6 Acids and Alkalis 6.1 Acids and Alkalis 6.2 Neutralisation Chapter 6 Magnetism and Electromagnetism 6.1 Magnets and Magnetism 6.2 Electromagnetism and Lorentz Force 6.3 Electromagnetic Induction 6.4 Transformers 6.5 Applications of Magnetism Chapter 7 Earth and the Solar System 7.1 The Solar System 7.2 Earth and Its Satellite Chapter 7 Structure of the Earth and Natural Disasters 7.1 Structure of Earth 7.2 Movement of Tectonic Plates Chapter 7 Pressure 7.1 Pressure 7.2 Pressure in Liquids 7.3 Gas Pressure Teacher’s Guide Focus-on Science Grade 7 v © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Grade 7 Grade 8 Grade 9 7.3 The Sun 7.3 Earthquakes 7.4 Volcanoes 7.4 Pascal’s Principle 7.5 Archimedes’ Principle 7.6 Bernoulli’s Principle 7.7 Osmosis and Osmotic Pressure 7.8 Applications of Pressure in Organisms Chapter 8 Soil 8.1 What is Soil? 8.2 Properties of Soil 8.3 Roles of Soil and Soil Organisms 8.4 Soil Formation 8.5 Conservation of Soil Developing Scientific and Thinking Skills The series promotes the inquiry-based learning method that adopts constructivist and contextual approaches to enable students to master science process skills and manipulative skills. This series also provides activities that develop higher-order thinking skills and the 21st century skills of students in their learning. Inquiry-based Learning Inquirybased Inquiry-based learning is a form of active learning that begins by posing questions, problems or situations, rather than simply presenting established facts and knowledge. In the classroom, students play an active role. They are empowered to pose questions, explore situations, gather information, solve problems, find solutions and communicate their results. They learn more by looking for an answer to a question. In addition, teachers may start with guided inquiry to build up background knowledge of the topic before letting the students take a role in developing their own inquiry. When carrying out inquiry-based activities, students work like scientists and acquire capabilities they need in their future lives. The key to effective scientific inquiry is to master scientific skills which are required to investigate and understand nature, to find solutions to problems and to make decisions in a systematic manner. Scientific skills comprise science process skills and manipulative skills. Science process skills are designed to provide a foundation for the mastering of science concepts and the development of thinking skills needed in the 21st century, while manipulative skills are the skills where students use basic tools in the learning of science. The mastering of science process skills together with scientific attitudes and appropriate knowledge ensure students’ ability to think effectively. The six basic science process skills that form the foundation of science lessons are: • Observation • Communication • Classification • Measurement • Inference • Prediction Teacher’s Guide Focus-on Science Grade 7 vi © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Constructivism Constructivism Constructivism helps students understand science better. Students are active learners. They construct their own understanding and knowledge of the world by reflecting on their personal experiences and by relating the new knowledge to what they have already learned. In the classroom, the focus tends to shift from the teacher to students. Teachers prepare students for lifelong learning. Students enjoy learning more when they are active participants rather than passive recipients of information. For example, a group of students are discussing a problem in science. The teacher focuses on helping them to restate their questions in useful ways even though he/she knows the “answer” to the problem. The teacher prompts the students to test their prior knowledge. The teacher lets the students explore and come up with relevant concepts. Constructivism focuses on learning how to think and understand. Students learn to question things and apply their curiosity to the world. Students communicate with others and share their understanding, knowledge and experience to come up with new knowledge. Contextual learning Contextual Contextual learning helps students to apply new knowledge and skills to real-life situations. Learning is relevant and meaningful when students can apply what they learn in the classroom to their daily life. Teachers can provide a lot of hands-on activities that help students to connect the content of knowledge to application. Students also learn from others through teamwork, discussions, cooperation and selfreflection. Some examples of contextual teaching and learning strategies include: • Using multiple contexts Learning experiences are enriched when students learn skills in multiple contexts such as school, community and family. • Problem-based Learning can begin with a simulated or real problem. Students use critical thinking skills to address and resolve the problem. • Encouraging self-learning Students are lifelong learners who seek out, analyse and use information with little to no supervision. Higher-Order Thinking Skills (HOTS) HOTS Higher-Order Thinking Skills (HOTS) is a concept of education reform that is mainly based on Bloom’s Taxonomy. The levels of thinking in Bloom’s Taxonomy, starting from the lowest to the highest are remembering, understanding, applying, analysing, evaluating and creating. When we talk about HOTS, we are concentrating on the highest four levels, namely, applying, analysing, evaluating and creating. Higher-Order Thinking Skills are activated when students encounter unfamiliar problems, questions or dilemmas. When they apply these skills, they can give explanations, make decisions and produce products that are valid within the context of available knowledge and experience. Appropriate teaching strategies and learning environment help students develop HOTS where they learn how to be self-directed, self-disciplined and self-monitored in their thinking process. Teacher’s Guide Focus-on Science Grade 7 vii © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Higher-Order Thinking Skills (HOTS) Lower-Order Thinking Skills (LOTS) Producing an original work Constructing, developing, designing, modifying Justifying a decision Judging, defending, evaluating, concluding Drawing connections among ideas Relating, organising, comparing, differentiating Using information in new situations Solving, predicting, demonstrating, applying Explaining ideas or concepts Summarising, classifying, discussing, identifying Recalling facts and basic concepts Recognising, listing, stating, defining BLOOM’S TAXONOMY CREATING EVALUATING ANALYSING APPLYING UNDERSTANDING REMEMBERING Source: Armstrong, Patricia. “Bloom’s Taxonomy”. Center for Teaching, Vanderbilt University, https://cft.vanderbilt.edu/guides-sub-pages/blooms-taxonomy/ Projects and activities should cover questions that challenge students to clarify their understanding, come up with reasons and pieces of evidence for their thinking, define their views and perspectives, determine consequences and evaluate concepts. Some ideas or activities that promote Higher-Order Thinking Skills are given below: • Applying – Predicting Given the weather report, students could be asked to predict the weather for the next day. • Analysing – Distinguishing Given a list of plant names, students could be asked to distinguish between the flowering plants and the non-flowering plants. • Evaluating – Judging Given some types of materials, students could be asked to judge them to identify which is the best conductor of heat. • Creating – Constructing Students could be asked to construct a model of a submarine. 21st Century Skills 21st Century skills The series is written to help teachers play their roles as facilitators of thinking and reasoning skills. 21st Century Skills are needed by students in order to succeed in the information age. Students should acquire these skills as they complement the science process skills. The 21st Century Skills include: • Critical thinking and problem-solving skills • Interpersonal and self-reliance skills • Information and communication skills Teacher’s Guide Focus-on Science Grade 7 viii © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

21st Century Skills can be practiced in the learning of science. Examples include: • Communication Students express their ideas and information in words, sounds and images in order to build shared understanding. • Integrating technology Students can apply computer and technology skills to learn and solve problems. Students possess the ability to learn quickly, process information accurately and use information in decision-making. STEM/Projects STEM Students can apply 21st Century skills in STEM activities or projects. STEM stands for science, technology, engineering and mathematics. STEM develops a set of thinking, creative reasoning, teamwork and investigative skills that students can use in their daily lives. A summary of the STEM acronym is as below: Science Focuses on the understanding of our environment, exploring and investigating the world using scientific skills, and critical and creative thinking skills. Technology Focuses on investigations using computers, tools and software applications. Engineering Focuses on solving problems using varied materials and designing, creating and building things that work. Mathematics Focuses on numbers and counting, space, sizes, shapes, measurements and patterns. Some examples of ideas for STEM project-based learning activities are given below: • Creating Earth’s model Students can create a model of the Earth using materials, such as clay, playdough and mashed paper. They can do all the steps by themselves and play a role in their learning. • Creating a hand pollinator Students learn to design, create and test a hand pollinator to transfer pollen grains from one flower to another. The STEM/Project-based activities aim to provide students the opportunities to work in small groups, search for information using technology, be critical in their judgment and decision making, create the endproduct and share with their peers to meet the needs of becoming the 21st century learners. By doing the projects, students explore themes and important issues such as climate change, health, technology and ethical issues of stem cell research. Through this process, students can take real action in addressing these issues based on their stages of learning, individual needs and contribute to their surrounding environment. Developing Scientific Attitudes and Noble Values Scientific attitudes and noble values can be inculcated through science activities. Students will have an interest and curiosity about their surroundings. They will develop an awareness of their responsibility to care for the environment. They learn to be systematic in carrying out activities, to be honest and Teacher’s Guide Focus-on Science Grade 7 ix © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

accurate in recording their observations or data. Examples of scientific attitudes and noble values that are important in the learning of science are: • Being responsible about the safety of oneself, others and the environment • Realising that science is a means to understand nature • Appreciating the contribution of science and technology • Appreciating and practicing clean and healthy living • Appreciating the balance of nature • Having critical and analytical thinking • Being respectful and well-mannered • Being confident and independent • Being thankful to God • Thinking rationally • Being cooperative • Being objective • Being flexible • Being caring • Daring to try Proper planning is required for effective inculcation of scientific attitudes and noble values during science lessons. Teachers should ensure that students carry out science activities in a careful, cooperative and honest manner during the lessons. Teacher’s Guide Focus-on Science Grade 7 x © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

How to Use the Focus-on Science Series The series is written to cater for the needs of lower secondary school students in developing scientific knowledge, skills, attitudes and noble values. The series provides key scientific information that makes the learning of science inquiry-based in order to develop scientific thinking and reasoning. The series consists of a Textbook, Workbook and a Teacher’s Guide. The Textbook and Workbook present core science topics in an activity-based environment to develop an inquiring mind in students. The Teacher’s Guide provides support for teachers to help students acquire the key knowledge and skills they need in order to understand and develop their creative and critical thinking skills in science. Textbook Each chapter begins with a highly colourful image to attract the students to the exciting content that follows. The purpose of the opening page is to encourage as much discussion as possible with the probing questions. It provides a good opportunity for teachers to assess students’ prior knowledge. It also tells the students what they are aiming to study. The key information in the text sets out the key facts and ideas that students need to know and understand. The content is presented with attractive visuals, pictures and diagrams to attract the attention of students and is linked directly to the learning objectives of the chapter. The key facts and ideas are reinforced by activities such as “Experiment”, “Activity”, “Project” and “Think About It”. These activities help students understand key ideas better and develop their scientific skills. They are required to work in pairs or small groups to present and share their findings with the whole class. Workbook The exercises provided in the Workbook are closely linked to the respective lessons in the Textbook to facilitate the teaching and learning process. The exercises are presented in a variety of formats and aimed at helping students learn more facts and understand the ideas and concepts better for each lesson. Two sets of assessment papers are included in the workbook to assess how well the students have understood the lessons learned. Teacher’s Guide The Teacher’s Guide is the main resource for teachers to start a chapter. It contains the scheme of work (lesson plan overview) that highlights the resources in the Textbook, Workbook and Teacher’s Guide for all the lessons in the chapter. The scheme of work also indicates the learning outcomes, suggested teaching approaches and estimated time allocation for each lesson in the chapter. The Teacher’s Guide provides guidelines to teachers on how to begin, develop and conclude the lessons in a chapter under several headings. Introduction Provide clear science information and facts to help teachers understand what they are going to teach in the chapter. Lessons and Learning Objectives Indicate all the lessons in the chapter and explain what students should know or do as a result of a learning experience. Teacher’s Guide Focus-on Science Grade 7 xi © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Key Terms Specific words or phrases that students are required to learn in the chapter. For each lesson in the chapter, the headings are: Learning Outcomes Describe the knowledge, skills or attitudes that students are expected to achieve after completing the lesson. Key Understanding Core ideas or concepts that students should gain from the lesson. Induction Engage students with the lesson and initiate whole-class discussion. The questioning technique is applied to elicit discussion and to find out what the students already know. Teaching and Learning Activities Set the lesson presentation mode. The activities include discussions, experiments and projects to enable students to master scientific concepts and skills, as well as develop scientific attitudes. Various approaches are suggested, including inquiry-based learning, contextual learning, experiential learning and collaborative learning. Assessment and Evaluation Gather information or evidence and make judgments about students’ learning and progress. Scoring rubrics are guidelines that teachers use to assess students’ performance in tasks, assignments or projects. They provide a standardised framework for evaluating different aspects of the work. Rubrics also provide feedback to students, highlighting their strengths and areas for improvement based on the defined criteria and scoring. Closure Help students reflect and consolidate their learning by summarising the key points of the lesson. Extension / Follow-up Activities Additional activities are provided to further enhance students’ understanding of the concepts and skills learned, making the learning experience more meaningful. Some of these activities include model making, games and quizzes, and research on current issues. Textbook Answers Detailed explanations or solutions provided for questions or problems in the Textbook, such as answers to the questions in “Experiment”, “Activity”, “Think About It”, “Recall” and “Put on Your Thinking Cap”. The answers to the “Exercises” in the Workbook are provided separately as a separate component. The URLs in the Teacher’s Guide were reviewed and deemed suitable at the time of publication. Teacher’s Guide Focus-on Science Grade 7 xii © Praxis Publishing Singapore Pte. Ltd. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 © Praxis Publishing Singapore Pte. Ltd. Skill Lacks proficiency (1) Partially proficient (2) Proficient (3) Advanced (4) Self-motivation Consistently fails to meet established deadlines. Takes initiative to complete assignments and improve or correct behaviours. Occasionally completes and turns in assignments before the scheduled deadline. Never misses a deadline and often completes assignments well ahead of deadlines. Communication Unable to speak or write clearly and to correct behaviours despite intervention by instructors, does not listen actively. Needs work to speak or write clearly; sometimes able to identify alternative communication strategies. Speaks clearly, writes legibly, listens actively and adjusts communication strategies to various situations. Comfortably utilises a variety of communication styles, writes legibly, speaks clearly and listens actively. Teamwork Manipulates the team or acts with disregard to the team, disrespectful to team members, resistant to change or refuses to cooperate in attempts to work out solutions. Sometimes acts for personal interest at the expense of the team, acts independent of the team or appears unsupportive, and is occasionally unwilling to work out a solution. Places the success of the team above self-interest, does not undermine the team, helps and supports other team members, and shows respect to all team members. Places success of the team above self-interest, takes a leadership role and uses good management skills while leading, and involves all team members in the decision-making process. Neatness The work appears sloppy and disorganised. It is hard to know what information goes together. The work is organised but may be hard to read at times. The work is neat and organised. It is easy to read. The work is neat, clear and organised. It is easy to read. Completion Most of the work is incomplete even when additional time or suggestions are given. Some work is incomplete and needs additional suggestions. Some work is incomplete and needs additional time. All work is complete. Responsibility Always relies on others to complete assignments. Rarely does the work and needs constant reminders to stay on the task. Rarely does the work and needs constant reminders to stay on the task. Always does assigned work without being reminded. Scoring Rubric for Affective Domain xiii ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 © Praxis Publishing Singapore Pte. Ltd. Skill Lacks proficiency (1) Partially proficient (2) Proficient (3) Advanced (4) State problem/ question Needs assistance to state the problem or identify the information. Sometimes states the problem or identifies the information correctly. Occasionally states the problem or identifies the information correctly. Works alone and correctly states the problem and identifies the information and the steps needed to arrive at a solution. Conclusion/ Synthesis thinking ability Conclusions drawn are lacking, incomplete or confusing and needs help to write a conclusion or answer questions. Sometimes asks for guidance to write or complete a conclusion. Occasionally answers questions and writes a conclusion in complete sentences. Always writes a response to whether the hypothesis is right or wrong and answers in complete sentences. Using scientific reasoning for explanation No evidence of scientific reasoning is used. Some pieces of evidence of scientific reasoning are used. Effective scientific reasoning is used. Employs refined and complex reasoning and demonstrates understanding of cause and effect. Using scientific concepts and related content Always relies on others in using scientific concepts. Provides minimal reference to relevant scientific concepts, principles or big ideas. Provides evidence of understanding of relevant scientific concepts, principles or big ideas. Provides evidence in depth and sophisticated understanding of relevant scientific concepts, principles or big ideas. Scoring Rubric for Scientific Thinking xiv ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 © Praxis Publishing Singapore Pte. Ltd. Skill Lacks proficiency (1) Partially proficient (2) Proficient (3) Advanced (4) Creativity The project has little creative and unique aspects. The project has some creative and unique aspects. The project has adequate creative and unique aspects. The project has plenty of creative and unique aspects. Communication and collaboration The information is not organised. Data is presented inaccurately. There is no drawing plan. Some information is clear and organised. There is a drawing plan without any labels. Most information is clear and organised. There is a clearly labelled drawing plan. All information and data are clear and organised. They are presented accurately. There is a clearly labelled drawing plan. Technology operations No technological resources are used in the project or are not used correctly. Few technological resources are used in the project or are not used correctly. Technological resources are used in the project correctly. Multiple technological resources are used appropriately. Teamwork Students demonstrate no cooperation, courtesy, enthusiasm, confidence or accuracy. Students demonstrate little cooperation, courtesy, enthusiasm, confidence or accuracy. Most students demonstrate some cooperation, courtesy, enthusiasm, confidence and accuracy. All students demonstrate high levels of cooperation, courtesy, enthusiasm, confidence and accuracy. Presentation Presentation lacks details needed to understand the team’s solution. Presentation provides an adequate explanation of how the solution is developed and how it works. Presentation or visual aids provide a clear, effective, and creative explanation of how the solution is developed and how it works. Presentation and visual aids provide a very clear, effective and creative explanation of how the solution is developed and how it works. Scoring Rubric for STEM Activities / Projects xv ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 xvi © Praxis Publishing Singapore Pte. Ltd. Chapter 1: Science and Measurements Lesson Learning outcomes Resources Time allocation Textbook Workbook Teacher’s Guide Approach 1.1 What is Science? • Explain what science is and its importance • Describe the relationship between science and society • Identify and describe the major branches of science • Recognise the different professions that exist within the field of science Activity 1: Scientists and their contributions (p. 6) Exercises 1−4 (pp. 1−2) Extra info: Artificial intelligence (AI) (p. 1) Induction (p. 2) Teaching and learning activities (p. 2) Assessment and evaluation (p. 3) Closure (p. 3) Extension / follow- up activities: AI and ML Career Exploration (p. 4) Textbook answers (p. 4) Activity 1: Inquiry Discussion about the AI and ML: Contextual AI and ML Career Exploration: Constructivism 8 periods (Weeks 1 & 2) 1.2 Science Laboratory • Differentiate the types of apparatus used in the laboratory • Identify and follow safety protocols and guidelines in a laboratory to ensure a safe work environment • Recognise the hazard warning symbols placed on the labels of bottles or containers • Plan a safe and fair test, and carry out the test via a scientific investigation with proper scientific attitudes and values Exercises 1−6 (pp. 3−5) Induction (p. 5) Teaching and learning activities (p. 5) Assessment and evaluation (p. 6) Closure (p. 6) Classification and handling of different types of apparatus: Experiential leaning Scientific investigation: The Effect of Different Fertilisers on Plant Growth: Inquiry, contextual learning 8 periods (Weeks 2 & 3) Scheme of Work [Note: The suggested teaching time can be altered according to the needs of the lessons.] ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 xvii © Praxis Publishing Singapore Pte. Ltd. Lesson Learning outcomes Resources Time allocation Textbook Workbook Teacher’s Guide Approach Extension / follow- up activities: Scientific investigation: The Effect of Different Fertilisers on Plant Growth (p. 7) Alternatives: • Create a poster of rules and safety precautions in a laboratory: Cooperative learning • Create a poster of hazard warning symbols, their meaning and handling techniques: Cooperative learning 1.3 Measurements • Define measurement and physical quantities • Name the base quantities and their SI units • Understand that derived quantities are formed from base quantities • Differentiate between base quantities and derived quantities • Know how to use prefixes and do the conversion of units Think About It (p. 14) Activity 2: Using non-standard and standard techniques to measure (p. 16) Exercises 1−3 (p. 6) Induction (p. 8) Teaching and learning activities (p. 8) Assessment and evaluation (p. 9) Closure (p. 9) Extension / followup activities: Relationship between Distance and Time (p. 9) Textbook answers (p. 10) Discussion about various everyday measurements and relate them to base quantities and derived quantities, and students’ reflection on how this knowledge can be useful in their daily lives: Constructivism Activity 2: Inquiry Relationship between Distance and Time: Inquiry, contextual 4 periods (Week 3) ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 xviii © Praxis Publishing Singapore Pte. Ltd. Lesson Learning outcomes Resources Time allocation Textbook Workbook Teacher’s Guide Approach 1.4 Measuring Tools • Describe the basic principles of measurement, including the concept of accuracy, consistency and sensitivity • Name and describe the uses of various measuring tools • Show proper use of measuring tools, including how to read and interpret scales, calibrate the tools and record measurements • Describe how measuring tools are used to obtain accurate and precise measurements • Develop skills in using the proper tools to measure length, area, volume, mass, time, temperature and density Think About It (p. 18) Activity 3: Measuring the volumes of solids (p. 22) Activity 4: Determining estimated measurements (pp. 24–25) Think About It (p. 26) Activity 5: Correct methods to use measuring tools (pp. 27–28) Activity 6: Comparing accuracy in measurements (pp. 29–31) Exercises 1−12 (pp. 7−12) Induction (p. 11) Teaching and learning activities (pp. 11–13) Assessment and evaluation (p. 13) Closure (pp. 13–14) Textbook answers (pp. 15–16) Students’ participation in class discussions by giving examples about measuring length, volume, mass, time, temperature and density: Constructivism Students’ participation in class discussions by giving scenarios about measuring area: Contextual Activity 3: Contextual Activities 4 to 6: Inquiry 14 periods (Weeks 3–5) End-of-chapter materials Recall (p. 32) Put on Your Thinking Cap (p. 33) Project: Scientific Investigations (p. 34) Objective Questions (pp. 13−14) Concept Map (p. 15) HOTS Daily Application (p. 16) Online Quick Quiz (p. 16) Textbook answers (pp. 16–17) Project Guide: Scientific Investigations (p. 17) Put on Your Thinking Cap & HOTS Daily Application: HOTS Scientific Investigations: 21st century skills 8 periods (Weeks 5 & 6) ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 xix © Praxis Publishing Singapore Pte. Ltd. Chapter 2: Matter Lesson Learning outcomes Resources Time allocation Textbook Workbook Teacher’s Guide Approach 2.1 States of Matter • Identify the three common states of matter (solid, liquid, gas) • Describe the arrangement and movement of particles in solid, liquid and gas, and their properties, including shape, volume, fluidity, compressibility and density • Explain the processes of melting, freezing, boiling, condensation, deposition and sublimation, and identify the temperature conditions at which they occur Activity 1: Matter has mass and occupies space (pp. 38−39) Activity 2: Arrangement and movement of particles in solids, liquids and gases (pp. 40−41) Think About It (p. 43) Experiment 1: Rate of diffusion in solids, liquids and gases (pp. 44−45) Experiment 2: Temperature remains constant during changes of state (pp. 48−50) Experiment 3: Mass remains constant during changes of state (pp. 50−52) Exercises 1−11 (pp. 17−24) Extra info: Water cycle (p. 23) Induction (p. 19) Teaching and learning activities (pp. 19-21) Assessment and evaluation (p. 21) Closure (p. 22) Extension / follow- up activities: Role of Carbon Dioxide in Climate Change (pp. 22–23) Textbook answers (pp. 23–25) Activities 1 & 2: Inquiry Discuss diffusion in the three states of matter: Contextual Experiments 1 to 3: Inquiry Research and present on a specific real-world scenario involving state changes: Contextual Role of Carbon Dioxide in Climate Change: Constructivism 12 periods (Weeks 7 & 8) ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 xx © Praxis Publishing Singapore Pte. Ltd. Lesson Learning outcomes Resources Time allocation Textbook Workbook Teacher’s Guide Approach 2.2 Physical and Chemical Changes • Explain the differences between physical and chemical changes • Identify the physical properties of matter that are involved in physical changes • Identify the indicators that show signs of chemical change • Analyse the physical and chemical changes in various everyday situations Think About It (p. 54) Think About It (p. 56) Activity 3: Physical and chemical changes in matter (p. 56) Exercises 1−3 (pp. 24−26) Extra info: Physical and chemical changes (p. 24) Induction (p. 25) Teaching and learning activities (p. 26) Assessment and evaluation (p. 26) Closure (pp. 26–27) Extension / follow- up activities: Chemical Reaction Investigation (p. 27) Textbook answers (pp. 27–28) Discuss physical and chemical changes as well as the properties of matter involved in these changes: Collaborative learning Compare and contrast physical and chemical changes, and identify the properties of matter involved in each type of change: Collaborative learning Activity 3: Inquiry Chemical Reaction Investigation: Inquiry/Simulation- based learning 2 periods (Week 8) 2.3 Density • Define density and describe how it is calculated • Identify whether an object will float or sink in a given fluid based on its density • Explain why some objects float and some objects sink in fluids Activity 4: Densities of different materials (p. 59) Activity 5: Sink or float (p. 60) Think About It (p. 60) Exercises 1−5 (pp. 26−28) Induction (p. 29) Teaching and learning activities (pp. 29–30) Assessment and evaluation (p. 30) Closure (p. 30) Activity 4: Collaborative learning Students’ participation in groups to measure the mass and volume of objects 6 periods (Week 9) ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 xxi © Praxis Publishing Singapore Pte. Ltd. Lesson Learning outcomes Resources Time allocation Textbook Workbook Teacher’s Guide Approach • Apply the knowledge of density to real-world situations Activity 6: Relationship between mass and density of various solids that have the same volume (p. 61) Activity 7: Determine the density of solids using water displacement method (p. 62) Textbook answers (pp. 30–31) and calculate their densities: Experiential learning Activity 5: Experiential learning, inquiry Activities 6 & 7: Inquiry End-of-chapter materials Recall (p. 63) Put on Your Thinking Cap (p. 64) Project: Build a Submarine Model (p. 65) Objective Questions (pp. 29−30) Concept Map (p. 31) HOTS Daily Application (p. 32) Online Quick Quiz (p. 32) Textbook answers (pp. 31–32) Project Guide: Build a Submarine Model (pp. 32–33) Put on Your Thinking Cap & HOTS Daily Application: HOTS Build a Submarine Model: 21st century skills 8 periods (Weeks 9 & 10) ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 1 © Praxis Publishing Singapore Pte. Ltd. Science and Measurements CHAPTER 1 Introduction Science and measurements are two basic concepts that drive our understanding of the natural world around us. Science is the systematic study of the natural world based on observation, experimentation and data analysis, whereas measurement is a means of measuring the value or magnitude of a physical quantity. In science, measurements are used to quantify and characterise the properties and behaviour of matter and energy. Scientists use measurements to characterise and understand the natural world, from the smallest subatomic particles to the greatest celestial objects. Accurate and exact measurements are critical in science. In this context, the science of measurements, plays a critical role in advancing scientific inquiry and innovation. Overall, science and measurements have always been interconnected concepts. Lessons and Learning Objectives 1.1 What is Science? • Explain what science is and its importance 1.2 Science Laboratory • Plan a safe and fair test, and carry out the test via a scientific investigation 1.3 Measurements • Name the base quantities and their SI units • Understand that derived quantities are formed from base quantities • Know how to use prefixes and do the conversion of units 1.4 Measuring Tools • Measure length, area, volume, mass, time, temperature and density using the proper tools Key Terms 1.1 scientific knowledge, technology, artificial intelligence, career 1.2 laboratory, rules, safety precautions, hazard warning symbols, scientific investigation, science process skills, scientific attitudes and values 1.3 measurement, physical quantities, SI units, base quantities, derived quantities, prefix, unit conversion 1.4 accuracy, consistency, sensitivity, length, area, volume, mass, time, temperature, density ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 2 © Praxis Publishing Singapore Pte. Ltd. Lesson 1.1 What is Science? Learning Outcomes • Explain what science is and its importance • Describe the relationship between science and society • Identify and describe the major branches of science • Recognise the different professions that exist within the field of science Key Understanding Science is a systematic and evidence-based approach to understand the natural world. The study of science involves observing occurrences, developing hypotheses, and evaluating those hypotheses and ideas through experiments. Scientific knowledge is based on observations and measurements that other scientists can repeat and verify. Science is a method of thinking and problem-solving that can be applied to a wide range of topics and disciplines. Science allows us to create new technology, better understand illnesses and diseases, and handle social problems such as climate change and energy generation. Induction 1 Use real-life examples to start the discussion of the importance of science in our daily lives. This includes examples of scientific discoveries that have resulted in technological improvements, such as the discovery of electricity and the development of electrical devices. Other than that, discuss about how scientific studies that have assisted humanity in understanding and addressing environmental challenges such as cause and effects of climate change, impact of pollution on the environment and human health, transmission of diseases and so on. 2 Encourage students to ask questions and participate in discussion on the importance of science to help them develop skills in critical thinking and examine what they think about science and its role in society. Teaching and Learning Activities Textbook p. 2 1 Introduce the terms such as science, scientific knowledge, technology and others to discuss about how science benefits us in various fields. Textbook pp. 3–4 2 Encourage students to discuss the popular apps they use to help them in their daily lives. 3 Explore the knowledge behind the apps they use that are actually the outcomes of artificial intelligence (AI) and machine learning (ML). 4 Introduce the concept of AI and ML by explaining and providing some examples. 5 Discuss the impact of AI and ML on society, such as how AI is changing the job market or how ML is being used to develop self-driving cars. 6 Let students analyse the ethical implications of AI and ML. For example, the concerns about privacy and data security. 7 Have students reflect on the impact of scientific discoveries on society. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 3 © Praxis Publishing Singapore Pte. Ltd. Textbook p. 5 8 Talk about the various branches of science, such as earth science, physics, chemistry and biology. Encourage students to list examples of careers in each discipline. 9 Ask them to think about how different fields of science have contributed to important discoveries and advancements in society. 10 Let them know that being a scientist is a profession that can relate to any of the disciplines discussed. There are many career paths they could pursue as a scientist. Textbook p. 6 11 Have students use the Internet to research more scientists and their contributions. Complete Activity 1 and share their findings in class. Assessment and Evaluation 1 Students’ understanding of artificial intelligence, different fields and careers in science can be assessed through their participation in class discussions. 2 Students’ research skills and presentation skills can be assessed through their research in completing Activity 1 and Extension / Follow-up Activities. 3 Students’ critical thinking skills can be assessed through their reflection and discussion of the ethical implications of AI and ML, and the impact of scientific discoveries on society. 4 Have students complete Exercises 1−4 Workbook pp. 1–2 . Students can get extra info on AI via the QR code given. 5 Provide feedback to students on their performance, highlighting areas where they have achieved and areas where they need to improve. Closure To summarise the important ideas and concepts taught in the lesson, consider using the key points provided through strategies such as a class discussion, a summary statement, a quiz, a visual organiser or a reflective writing assignment. Allow students to ask any additional questions for clarification or clear up any doubts. What is Science? 1 Science is an orderly method to understanding the natural world. 2 Scientists form explanations or models for natural occurrences by observation, experimentation and logical reasoning. Artificial Intelligence (AI) 3 Artificial intelligence (AI) is a branch of computer science that seeks to develop intelligent machines capable of performing activities that normally require human intelligence, such as interpreting natural language, recognising images and making decisions. 4 Machine Learning (ML) is a branch of artificial intelligence that focuses on creating algorithms and models that can learn from data rather than being explicitly programmed to do a specific task. 5 AI and ML have a wide range of applications, including picture and speech recognition, natural language processing, autonomous cars and predictive analytics. 6 There are also ethical concerns with AI and ML, such as data and decision-making bias, job displacement and the possibility of misuse. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 4 © Praxis Publishing Singapore Pte. Ltd. Fields and Careers in Science 7 Different branches of science exist, such as physics, chemistry, biology, earth science and so on. 8 Many key discoveries and advances in society have been made possible by science, such as the discovery of vaccinations, technology and our understanding of the natural world. Extension / Follow-up Activities AI and ML Career Exploration 1 Group the students into smaller groups. Give each group a distinct scientific discipline, such as cosmology, engineering, physics, chemistry or geology. 2 Ask each group to choose an occupation within their field and do research about that occupation which involves AI or ML. For example, a group of biology students might decide to pursue a career as a bioinformatics analyst, which involves utilising computational techniques to analyse biological data. 3 Once each group has chosen a career, ask them to come up with a brief presentation outlining the duties of the position, how AI and ML are utilised in the industry, and what abilities or qualifications are necessary for the position. 4 After the presentations, lead a discussion on the various applications of AI and ML in science and their potential effects on current and upcoming discoveries and scientific study. 5 Encourage students to consider their personal interests, abilities and how they may choose a scientific career that uses AI or ML. To assist students in furthering their exploration of possible career pathways, offer resources like job listings or internship opportunities. Textbook Answers Activity 1 p. 6 1 & 2 A Albert Einstein – (d) B Sir Isaac Newton – (a) C Alexander Graham Bell – (c) D Alexander Fleming – (b) 3 Grace Hopper – She was a computer programming pioneer who created one of the first linkers. Charles Kao – He was a physicist and electrical engineer who pioneered the development and use of fibre optics in telecommunications. Lesson 1.2 Science Laboratory Learning Outcomes • Differentiate the types of apparatus used in the laboratory • Identify and follow safety protocols and guidelines in a laboratory to ensure a safe work environment • Recognise the hazard warning symbols placed on the labels of bottles or containers • Plan a safe and fair test, and carry out the test via a scientific investigation with proper scientific attitudes and values ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 5 © Praxis Publishing Singapore Pte. Ltd. Key Understanding Differentiating different types of laboratory apparatus is important for ensuring that the correct apparatus is used for specific investigations. On the other hand, recognising hazard warning symbols is essential for identifying potential risks and hazards corresponding with certain chemicals or materials. When carrying out an experiment, it is important to follow safety regulations and guidelines in order to ensure a safe working environment and reduce the possibility of accidents. Planning a safe and fair test through a scientific investigation requires adhering to ethical standards and ensuring the experiment is welldesigned and controlled, with accurate observations and correct results. Overall, a thorough awareness of laboratory apparatus, hazard warning symbols, safety regulations, and scientific attitudes and values is essential for successful and safe experimentation. Induction 1 Introduce the topic and learning outcomes of the lesson. 2 Highlight the importance of laboratory safety rules and precautions to the students and stress the importance of the right scientific attitudes and values for successful experimentation. Teaching and Learning Activities Textbook pp. 7–8 1 Group students into five groups. 2 Allow them to identify different types of apparatus, such as apparatus used for: (a) containing, collecting and transferring chemicals (b) measuring the volume of liquids (c) filtering and evaporating (d) heating (e) holding and supporting apparatus 3 Request a representative from each group to list the classification of the laboratory apparatus onto the board. Then, discuss the outcomes in class. 4 Show students how to safely handle the apparatus to prevent accidents. Textbook pp. 8–9 5 Students discuss the rules and safety precautions that they must follow while in the laboratory. Emphasise the importance of wearing safety goggles, gloves and lab coats when handling specific chemicals, as well as ensuring proper disposal of chemicals. 6 Students explore the various hazard warning symbols, their meanings and handling techniques. They learn how to read and interpret labels on chemical containers to identify potential risks and hazards. Textbook pp. 10–13 7 Explain the steps on how to plan a safe and fair test in carrying out a scientific investigation. Students identify the science process skills involved in each step. 8 Explain to students the importance of scientific attitudes and values such as objectivity, openmindedness and precision in conducting experiments. 9 Review the key concepts and learning outcomes of the lesson. 10 Provide them with scientific investigation worksheets to apply the knowledge they have learned. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 6 © Praxis Publishing Singapore Pte. Ltd. Assessment and Evaluation 1 Assess students’ understanding of the types and uses of laboratory apparatus through their participation in class activity, Workbook p. 3 . 2 Assess students’ ability to identify hazard warning symbols, and understanding of safety protocols and guidelines in a laboratory Workbook pp. 4–5 . 3 Review students’ scientific investigation worksheets to evaluate their understanding of scientific attitudes and values in carrying scientific investigations Workbook p. 5, Extension / Follow-up Activities . 4 Provide feedback to students on their performance, highlighting areas where they have achieved and areas where they need to improve. Closure • To summarise the important ideas and concepts taught in the lesson, consider using the key points provided through strategies such as a class discussion, a summary statement, a quiz, a visual organiser or a reflective writing assignment. Allow students to ask any additional questions for clarification or clear up any doubts. Laboratory Apparatus, Safety Precautions and Hazard Warning Symbols 1 Laboratory apparatus is essential for scientific investigations. Each apparatus serves a particular purpose and is designed for carrying out a specific activity. 2 It is important to use the proper apparatus for the intended purpose and to handle it with care and safely. Proper laboratory apparatus maintenance and calibration are also required for precise and reliable findings. 3 There are rules and safety precautions that the students must follow while they are in the laboratory. 4 Hazard warning symbols are frequently seen on containers, tools and signs in laboratories to indicate the presence of potentially dangerous substances or conditions. 5 The commonly seen symbols are flammable, corrosive, toxic, radioactive and explosive. 6 When working with potentially hazardous substances or conditions, it is important to understand the meaning of these symbols and to take the proper safety precautions. Scientific Investigations, Scientific Attitudes and Values 7 The scientific investigation is a framework that describes the general steps scientists usually take to look into an issue or phenomenon. Scientific investigation required the mastery of science process skills. 8 Scientists deliver explanations or models for occurrences in nature using observation, experimentation and logical thinking. 9 Scientific explanations must be testable and verifiable, meaning they can be subjected to further testing and potentially shown incorrect. 10 A set of attitudes and values, including curiosity, objectivity, precision and honesty, serves as the foundation for scientific investigation. • Inform the students that the knowledge and skills gained from this topic will be useful in future topics both in this level and at higher levels of education. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 7 © Praxis Publishing Singapore Pte. Ltd. Extension / Follow-up Activities Plan your own investigation or let students carry out the following investigation in small groups. Scientific investigation worksheets: The Effect of Different Fertilisers on Plant Growth Aim: To identify the fertiliser that best stimulates the plant growth Hypothesis: Plants fertilised with organic fertiliser will grow faster than plants fertilised with inorganic fertiliser or no fertiliser. Materials: three small pots, measuring cup, ruler, soil, seeds of the same plant (for example, green bean seeds), organic fertiliser, inorganic fertiliser, water Procedure: 1 Label the three pots as follows: (a) Organic fertiliser (b) Inorganic fertiliser (c) No fertiliser 2 Fill each pot to the same level with soil. 3 Plant one seed in each of the pots. 4 Fill the pots labelled with the matching fertiliser type with the right type of fertiliser. 5 Place all of the pots in a sunny spot. 6 Water the plants in each of the pots with the same amount of water every day. 7 Record the days the seedlings start to grow in each pot. Make an inference on why the seedlings grow. 8 Modify your steps if there is no sign of seedling growth. 9 Once a week, use a ruler to measure and record the height of each plant. 10 Observe the plants’ appearance, such as the colour of the leaves, the number of leaves or the presence of any pests or illnesses. 11 For the next three weeks, continue to examine and measure the plants. Data analysis: 1 Make a table to record your observation about the plant growth for each pot. 2 At the end of each week, calculate the average height of the plants in each pot. 3 Make a bar graph to compare the average height of the plants in each pot. 4 Analyse the data and draw a conclusion regarding the influence of various fertiliser types on plant growth. Conclusion: Write a conclusion that summarises the experiment’s findings and whether the hypothesis was accepted or rejected. Include any suggestions for future improvements to the experiment. Lesson 1.3 Measurements Learning Outcomes • Define measurement and physical quantities • Name the base quantities and their SI units • Understand that derived quantities are formed from base quantities ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 8 © Praxis Publishing Singapore Pte. Ltd. • Differentiate between base quantities and derived quantities • Know how to use prefixes and do the conversion of units Key Understanding Base quantities are fundamental physical quantities that cannot be expressed in terms of other physical quantities. Base quantities include length, mass, time, electric current and temperature. These fundamental quantities are expressed in terms of their respective base units, such as metre (m) for length, kilogram (kg) for mass, second (s) for time, ampere (A) for electric current and kelvin (K) for temperature. On the other hand, derived quantities are physical quantities that can be expressed in terms of one or more base quantities. For instance, speed, which is distance/time, is a derived quantity, and its unit is metres per second (m/s). Acceleration, force, energy and power are some of the examples of derived quantities. To convert units of physical quantities, we need to apply conversion factors that link different units of the same physical quantity. To ensure that the final solution has the correct units, it is essential to use conversion factors accurately and keep track of the units in calculations. Induction Textbook p. 14 1 Get students to answer the following questions to gauge their prior knowledge. (a) What is a physical quantity? Could you give an example? (b) What are some of the most common physical quantities you are familiar with? (c) What is a measurement unit? Suggest an example. (d) What are the SI units? What is their importance in science? 2 Allow students to respond to the questions, then look over their responses and provide more information as needed to assist identify any gaps in understanding. Then, let them answer the question in ‘Think About It’. Teaching and Learning Activities Textbook pp. 15–16 1 Hold a discussion and get students to give various everyday measurements (length, mass, time, temperature and so on) and the SI units used to measure them (metre, kilogram, second, Celsius and so on). 2 Ask whether they understand what a base quantity is and how it differs from a derived quantity. 3 Explain to them that base quantities are independent physical quantities that can be measured directly, whereas derived quantities are physical quantities that are generated from base quantities by mathematical operations. 4 Use the examples of base quantities (length, time and so on) given by students and encourage them to show how some of the derived quantities such as velocity and acceleration can be obtained. 5 Let students work in pairs to measure objects of different sizes or shapes using different measuring apparatus and carry out Activity 2. 6 Then, ask them to identify the base quantities in Activity 2, and present to the class how the combination of these base quantities can generate derived quantities. Discuss the answers to the questions in Activity 2. 7 Ask the students if they know what a prefix is and how it is used to convert between units of measurement. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 9 © Praxis Publishing Singapore Pte. Ltd. 8 Give examples of prefixes, their numerical values / conversion factors (for example, milli = 0.001, centi = 0.01, kilo = 1000 and so on) and examples of converting between units using prefixes (for example, from millimetres to kilometres or vice versa), and demonstrate the steps involved. 9 Ask the students to reflect on how the knowledge of base quantities, derived quantities, prefixes and unit conversion can be useful in their daily lives. Assessment and Evaluation 1 Observe how students participate in class discussions and activities. 2 Evaluate the accuracy and completeness of the students’ responses during the presentation. 3 Have students complete Exercises 1–3 Workbook p. 6 . 4 Assess students’ critical thinking skills, scientific skills, attitudes and values in the Extension / Followup Activities. 5 Provide feedback to students on their performance, highlighting areas where they have achieved and areas where they need to improve. Closure To summarise the important ideas and concepts taught in the lesson, consider using the key points provided through strategies such as a class discussion, a summary statement, a quiz, a visual organiser or a reflective writing assignment. Allow students to ask any additional questions for clarification or clear up any doubts. Measurement 1 The process of measurement involves the assignment of numbers and units to observable phenomena for descriptive purposes. Physical Quantities 2 Physical quantities are quantities that can be measured and expressed using numbers and units. The International System of Units (SI) is the most widely used system of measurement. 3 Physical quantities are classified into base and derived quantities. Base Quantities 4 Base quantities are length, time, mass, electric current and temperature. They are the most basic and cannot be defined in terms of other quantities. Derived Quantities 5 Derived quantities are derived from base quantities using mathematical operations. Velocity, volume and density are some of the examples of derived quantities. Prefixes and Conversion of Units 6 Prefixes are used to change a unit’s scale by multiples of 10, making it simpler to describe very big or very small quantities. 7 The prefixes kilo-, mega-, giga-, milli-, micro- and nano- are the most frequently used prefixes. 8 The ratio of the two prefixes, with the smaller prefix in the denominator and the bigger prefix in the numerator, is the conversion factor used to convert between units with distinct prefixes. 9 For instance, to convert 3 km to m, multiply 3 by 1000 to get 3000 m as 1 km is equal to 1000 m. Extension / Follow-up Activities Relationship between Distance and Time Have students develop and carry out an inquiry-based experiment in which they need to measure and analyse physical quantities. For example, study the relationship between distance and time by measuring the time it takes a toy car to drive different distances and then determining the speed of the car in different units of measurement. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 10 © Praxis Publishing Singapore Pte. Ltd. You can guide students through the steps as follows: 1 Determine the learning objectives: What specific knowledge and skills do you want students to acquire as a result of this activity? Do you want them to learn about the relationship between distance, time and speed, be able to measure physical quantities and use unit conversion to represent speed in other units? 2 Identify apparatus and material: For example, toy car, metre rule or measuring tape, stopwatch, calculator or any other items that may be needed. 3 Design the experiment: Plan the steps, including how the toy car will be moved, how far it will travel and how the time will be measured. Consider how to control variables that may affect the results of the experiment, such as the surface on which the car is travelling, the slope of the surface and the car’s weight. 4 Conduct the experiment: Ensure that students understand the procedures of the experiment and safety measures to be taken care of. Students should work in small groups to time how long it takes the toy car to go different distances and record the results in a table. 5 Analyse the data: Ask the students to analyse the data they collected, calculate the speed of the toy car using different units of measurement such as metres per second and feet per minute. Ask them to compare the results, as well as identify any patterns. 6 Draw conclusions: Ask the students to make conclusions based on their data analysis. Did the toy car’s speed vary with distance travelled? Were there any challenges in the students’ measurements or calculations? 7 Reflect and report: Ask students to reflect on what they have learned and communicate their findings in the form of a written report. Textbook Answers Think About It p. 14 We measure temperature, time, length and mass. Activity 2 p. 16 1 & 2 Student’s answers 3 Using standard techniques 4 The standard techniques can resolve the issues of confusion and misunderstanding in terms of measurements for people in different places. Lesson 1.4 Measuring Tools Learning Outcomes • Describe the basic principles of measurement, including the concept of accuracy, consistency and sensitivity • Name and describe the uses of various measuring tools • Show proper use of measuring tools, including how to read and interpret scales, calibrate the tools and record measurements • Describe how measuring tools are used to obtain accurate and precise measurements • Develop skills in using the proper tools to measure length, area, volume, mass, time, temperature and density ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 11 © Praxis Publishing Singapore Pte. Ltd. Key Understanding A measuring tool is a tool that is used to determine the dimensions of an object or material. Measuring tools come in a variety of designs and sizes. Micrometers, calipers, weighing scales and thermometers are some of the examples. These tools are used to measure length, mass and temperature. The accuracy and precision of measuring tools are critical for ensuring consistent and reliable measurements. For getting precise results, the correct measuring tools must be used properly. This includes using the correct technique and preventing tool damage. Induction Textbook p. 17 1 Activate students’ prior knowledge by asking them if they have ever measured anything before, and if yes, how they did it. 2 Explain how measuring tools are used to determine the physical dimensions of objects or materials. 3 Introduce to them the three important aspects which are accuracy, consistency and sensitivity in measurement. Teaching and Learning Activities Textbook p. 18 1 Ask the students if they understand what the term ‘length’ means. Discuss the definition of length as a measurement of how long something is. Request the students to give examples of objects they can measure the length. 2 Explain the concept of length and how eye position affects reading with a ruler. 3 Get students to look at the picture of the infant and let them answer the questions in ‘Think About It’. Then, go through the ‘Science Facts’ with them. Textbook pp. 19–20 4 Introduce to them the measuring tools, such as vernier calipers and micrometer screw gauge which are used to measure the thickness and diameter of small objects. 5 Show them the correct way of using these tools. Remind students that they must always check for zero error before using the tools to get accurate reading. Get them to read through the ‘Science Facts’ about the digital calipers and micrometer screw gauges. Textbook pp. 20–21 6 Explain what the term ‘area’ means and help students to recall its unit by relating it to the derived quantity. 7 Let them know that if the object has a regular shape, like a square or a rectangle, they can find the area by measuring its length and width and using easy multiplication. If we need to find the area of an irregular shape, we can use graph paper to estimate. 8 Give one or two situations, such as carpeting a room and building roads, and explain that we need to calculate areas for different reasons. Then, ask students to provide more scenarios and to think of reasons why they need to find the area of something. Remind them that it is important to use the right unit. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 12 © Praxis Publishing Singapore Pte. Ltd. Textbook pp. 21–22 9 Get volunteers to explain if they know what ‘volume’ means. Discuss the definition of volume as a measure of how much space an object occupies. 10 Students give examples of objects they can measure the volume and the unit of measurement. 11 Explore the different volume measurement units, such as millilitres and cubic metres, and how they relate to one another. 12 Explain to students on the proper method for measuring the volume of liquids and the correct way of taking accurate readings. Emphasise to students that they have to pay attention to the correct eye position when taking readings of liquids and mercury. Textbook p. 22 13 Discuss the water displacement method for measuring the volume of regular-shaped and irregularshaped solids. 14 Engage students in Activity 3 to further reinforce their understanding of this method. 15 Have them read the ‘Science Facts’ about Archimedes, who determined if a crown was made of pure gold or not by comparing its density to that of gold. Textbook p. 23 16 Ask students to share their understanding of the difference between mass and weight. Find out if they are familiar with any tools or units used to measure them. Then, introduce the concepts of mass and weight. 17 Facilitate a discussion on the relationship between mass and weight, highlighting their similarities and differences. Have students work in pairs or small groups to create a comparison table, and then have volunteers share their tables with the class. Textbook pp. 24–25 18 Have students work in groups to measure the length, area and mass of different objects in Activity 4. 19 Discuss the results as a class and compare the measurements obtained. 20 Go through the discussion questions with students and ask them to reflect on what they learned about measuring the length, area and mass. Textbook p. 25 21 Divide students in groups. Give them a stopwatch and show them how to use it. 22 Allow students to practise using stopwatches to time themselves doing simple tasks, such as walking from one end of the room to the other or solving a simple math problem. Textbook p. 26 23 Ask students about their understanding of temperature and how it is measured. 24 Introduce the concept of temperature and its different units of measurement. 25 Get them to learn how to read a thermometer by answering the question in ‘Think About It’. 26 Before introducing the concept of density, ask what students know about density and what it means. 27 Explain the concept of density by introducing its formula and SI unit. Let them know that they will learn this concept in more detail in Chapter 2 and get them to try out the question in ‘Think About It’. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 13 © Praxis Publishing Singapore Pte. Ltd. Textbook pp. 27–31 28 After introducing all the concepts of measuring length, area, volume, mass, time, temperature and density, emphasise to the students that measuring is an important skill in scientific investigations. Tell them to use suitable measuring tools, the right techniques and take at least three readings when measuring. 29 Let them carry out Activities 5 and 6 to strengthen their skills in using the correct methods to use measuring tools and compare the accuracy of measuring tools. Assessment and Evaluation 1 Assess students’ understanding of all concepts by observing their participation in class discussions, whether they provide examples, scenarios, share their thoughts, or work in pairs or small groups. 2 Assess students’ understanding of the concepts learned as well as their scientific and critical thinking skills, attitudes and values, through observation of their participation during Activities 3 to 6 and review their results, discussions and conclusions. 3 Have students complete Exercises 1−12 Workbook pp. 7–12 . 4 Provide feedback to students on their performance, highlighting areas where they have achieved and areas where they need to improve. Closure • To summarise the important ideas and concepts taught in the lesson, consider using the key points provided through strategies such as a class discussion, a summary statement, a quiz, a visual organiser or a reflective writing assignment. You may also ask students to summarise them in their own words. Allow students to ask any additional questions for clarification or clear up any doubts. Measuring Tools 1 Measuring tools are used to measure physical quantities such as length, mass, volume and time. The following are the important things to remember when using measuring tools: (a) Accuracy (b) Consistency (c) Sensitivity (d) Units of measurement (e) Zero errors (f) Use suitable tools and the right techniques (g) Repeat the measurement Measuring Length 2 Select the correct measuring tool for the length to be measured. For example, a measuring tape is suitable for measuring long distances, whereas a ruler or caliper is suitable for measuring short lengths. 3 To obtain the correct reading, ensure the eyes are vertically above the mark on the measuring tool to avoid parallax error. 4 Check the measuring tool for zero error before taking a measurement. Before taking measurements, make sure that the tool is correctly calibrated and adjusted. Measuring Area 5 The area of objects with regular shapes such as a rectangle and a circle can be calculated using mathematical formulae. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 14 © Praxis Publishing Singapore Pte. Ltd. 6 The area of an object with an irregular shape such as a piece of leaf can be estimated by tracing its shape on graph paper. Then the number of squares that are fully covered, half-covered and more than half-covered are counted. Measuring Volume 7 The measuring tool we use should be suitable for the volume being measured. For example, a measuring cylinder is suitable for measuring small volumes. 8 It is important to correctly read the meniscus, which refers to the curved surface of a liquid in a container. The volume is measured at the bottom of the meniscus, except for mercury where its volume is measured at the top of the meniscus. 9 The volume of regular-shaped and irregular-shaped solids can be measured by using the water displacement method. Measuring Mass 10 A beam balance or a lever balance is suitable for measuring small masses. 11 Before taking a measurement, ensure that the measuring tool is zeroed. This means that when there is nothing on the scale or balance pan, the measuring tool should be adjusted to read zero. Measuring Time 12 A stopwatch is suitable for measuring short durations. 13 Make sure the tool is properly calibrated and that we can start the timer and stop it carefully and correctly. 14 When measuring time, it is important to use the correct units of measurement. Depending on the application, time can be measured in seconds, minutes, hours or days. Measuring Temperature 15 A thermometer can be used to measure low to medium temperatures. 16 When measuring temperatures, it is important to use the proper units of measurement. For example, the temperature can be measured in degrees Celsius, Fahrenheit or Kelvin, depending on the purpose. Measuring Density 17 A hydrometer is used to determine the density of liquids. 18 We can determine the density of an object or substance by determining its mass and volume. A balance or scale can be used to measure mass, while a measuring cylinder, burette or displacement method can be used to measure volume. 19 Once the mass and volume have been determined, the density can be calculated using the formula density = mass/volume. • Ask students to reflect on what they have learned in this chapter by completing the sections ‘Recall’ Textbook p. 32 and ‘Concept Map’ Workbook p. 15 . • Let students complete the ‘Objective Questions’ Workbook pp. 13–14 and ‘Online Quick Quiz’ Workbook p. 16 to check their mastery of this chapter. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 15 © Praxis Publishing Singapore Pte. Ltd. • To reinforce students’ critical thinking skills, have them answer the questions in ‘Put on Your Thinking Cap’ Textbook p. 33 and ‘HOTS Daily Application’ Workbook p. 16 that require them to analyse, evaluate or create based on the knowledge they have acquired. • Give students a preview of what will be covered in the upcoming chapter to help them get ready. Textbook Answers Think About It p.18 Measuring tape because the tape is flexible. Activity 3 p. 22 3 Final reading – initial reading 4 Water displacement method 5 (a) Put a weight in a measuring cylinder filled with water. (b) Take the reading of the water level (initial reading). (c) Attach the cork to the weight with a thread. Lower them into the measuring cylinder. (d) Take the reading of the water level (final reading). (e) Volume of cork = final reading – initial reading 6 Eureka can Activity 4 p. 24 Discussion: 1 Length is the distance between two points. 2 No 3 Area is the total surface covered by an object. 4 Area = Length × Width 5 No 6 The estimated area of the object will be more accurate. 7 Mass is the quantity of matter in an object. 8 Using 500 pieces of A4 paper Conclusion: Estimated reading is different from the actual reading of a measurement. Think About It p. 26 • The correct way to read a thermometer is by positioning the eye at the same level as the meniscus of mercury. • This is because the density of helium gas is less than the density of air. Activity 5 p. 27 Discussion: 1 To get a more accurate value. 2 (a) Second box, 6 cm (b) Second box, 27 ml (c) Second box, 25 ml (d) Second box, 94°C ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 16 © Praxis Publishing Singapore Pte. Ltd. 3 2, 3, 1, 4 4 Zero error and parallax error Conclusion: 1 several 2 vertically 3 meniscus Activity 6 p. 29 Discussion: Measuring tool Accuracy (a) Vernier calipers 0.01 cm (b) Digital vernier calipers 0.01 mm (c) Micrometer screw gauge 0.01 mm (d) Digital micrometer screw gauge 0.001 mm (e) Clinical thermometer 0.5°C (f) Digital thermometer 0.1°C (g) Triple beam balance 0.05 g (h) Digital balance 0.01 g Conclusion: accurate Recall p. 32 1 science, technology 2 apparatus 3 safety 4 symbols 5 scientific 6 measurement 7 physical 8 base 9 derived 10 conversion 11 metre 12 thickness, diameters, depth 13 square metre 14 volume 15 displacement 16 mass, weight 17 stopwatch, second ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 17 © Praxis Publishing Singapore Pte. Ltd. 18 temperature, kelvin, thermometer 19 kg m–3 Put on Your Thinking Cap p. 33 1 The unused chemical may be contaminated. Pouring it back into its bottle will contaminate the whole bottle of chemical. 2 39.37 inches 3 (a) Mass: Remains the same at all places. Weight: Varies according to places. (b) No. The mass of an object remains the same in all places, whether on the Earth or the Moon. Project: Scientific Investigations Textbook p. 34 1 Introduction (a) Introduce the concept of scientific investigation. (b) Explain to students that they will carry out their own scientific investigation at home. (c) Give a brief overview of the steps involved in conducting a scientific investigation. (developing a hypothesis, carrying out the experiment, collecting and analysing data, and drawing a conclusion). 2 Material selection (a) Instruct students to examine the materials they have at home. (b) Ask students to choose one material and start asking questions about the material. (c) Encourage students to identify one question they want to answer through scientific investigation. 3 Investigation planning and execution (a) Instruct students to plan their investigation using the steps stated in their textbook [Procedure: 3(a) to (h)]. (b) Provide guidance and support as needed during the planning process. (c) Instruct students to carry out their investigation at home. (d) Encourage students to follow their investigation plan carefully. (e) Remind students to record their observations and data accurately. 4 Reflection and presentation (a) Instruct students to reflect on their investigation using the questions stated in their textbook. Then, write a complete report of the investigation based on the standard format. (b) Allow students to share their investigation and results with the class through a presentation. They can discuss the similarities, differences in their investigation, and results with their peers. 5 Assessment Assess students based on their investigation plan, execution and report with the following criteria. (a) The clarity and completeness of the investigation plan (b) The accuracy and completeness of the data collected (c) The quality of the analysis and conclusions drawn (d) The effectiveness of the report in communicating the investigation and results ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 18 © Praxis Publishing Singapore Pte. Ltd. Matter CHAPTER 2 Introduction Objects are composed of matter. From the air we breathe to the ground we step on, matter is all around us. It is something that has mass and occupies space. In this chapter, we will explore deeper into matter’s characteristics, including its physical and chemical properties. We will study the states of matter and some of their properties, and how they can change from one form to another. We will also look at how the states of matter can lead to physical and chemical changes as well as the concept of density and how it relates to matter’s behaviour, such as floating and sinking. By the end of this chapter, students will have a firm grasp on the fundamental principles of matter and how they work. Lessons and Learning Objectives 2.1 States of Matter • Describe the arrangement and movement of particles in solid, liquid and gas, and their properties • Explain what happens in changes of state using the particle theory 2.2 Physical and Chemical Changes • Describe the physical and chemical changes 2.3 Density • Define density and calculate the density of a material • Explain why some objects float and some objects sink in water Key Terms 2.1 discrete, constant motion, solid, liquid, gas, diffusion, melting, freezing, boiling, condensation, deposition, sublimation, evaporation 2.2 physical characteristics, chemical characteristics, physical changes, chemical changes 2.3 density, float, sink ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 19 © Praxis Publishing Singapore Pte. Ltd. Lesson 2.1 States of Matter Learning Outcomes • Identify the three common states of matter (solid, liquid, gas) • Describe the arrangement and movement of particles in solid, liquid and gas, and their properties, including shape, volume, fluidity, compressibility and density • Explain the processes of melting, freezing, boiling, condensation, deposition and sublimation, and identify the temperature conditions at which they occur Key Understanding Matter can exist in three common states: solid, liquid and gas, each with its own properties determined by particle arrangement and intermolecular forces. Solids have a fixed shape and volume because their particles are tightly packed together and vibrate in place. Liquids, on the other hand, have a fixed volume but take on the shape of their container due to the ability of their particles to move freely. For gases, they have no fixed shape or volume because their particles are far apart and move randomly. The state of matter can change due to processes influenced by temperature and pressure, such as melting, freezing, boiling, condensation, deposition and sublimation. Induction 1 Begin by asking the students if they are familiar with what matter is. Encourage them to provide examples of the three common types of matter that can be found in their daily lives. Allow them to ask questions if they need to clarify any doubts. 2 Explain to the class that matter can exist in different states and guide them in exploring three of the most common states: solid, liquid and gas. 3 Select three volunteers and give each of them one balloon. Before assigning each of them one of the tasks below, have the class predict what will happen when they (a) heat the balloon (b) cool the balloon (c) leave the balloon at room temperature 4 Then, let the volunteers conduct this simple test to verify if the prediction is accurate. Teaching and Learning Activities Textbook pp. 36–37 1 Start with solid matter. Show the students some objects in the shape of cubes, cuboids or cylinders. Ask them to identify the properties such as shape, volume, fluidity, compressibility and density. Pass around these objects for the students to touch and feel. Ask students whether the shape and volume of these objects can change when they are placed in some other places/containers, or when being pressed. Guide the students until they can conclude that a solid has a definite shape and volume. Ask students to give examples of other solids and explain why they are solids. 2 Proceed to liquid matter. Display a dish of ice cubes to the students and ask them to identify their properties. Pass the ice cubes around as well. Explain that ice cubes are solids that melt to form water, which is a liquid. Ask students whether the shape and volume of water can change when it is poured into other containers of different shape. Guide the students until they can conclude that water has a ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 20 © Praxis Publishing Singapore Pte. Ltd. definite volume but takes the shape of its containers. Ask students to give examples of other liquids and explain why they are liquids. 3 End with gas matter. Ask students to describe the properties of a balloon after it has been inflated. Explain that the balloon is filled with gas and guide the students until they can conclude that a gas has no fixed shape and volume. Get students to give examples of other gases that they are familiar with. 4 In groups, students create a chart to compare and contrast the properties of the three states of matter, including the shape, volume, fluidity, compressibility and density. Display the charts in a prominent area in the classroom. 5 Gather students to review the properties of each state of matter of all the groups and ask them to give examples of each state. 6 Go through the text in the textbook with the students, then discuss the displayed charts and have them fill in any missing properties. 7 Emphasise to them that while solids typically have the highest density, there is an exceptional case for water. The density of ice is lower than that of liquid water, which is a unique property of water due to the arrangement of water molecules in a solid versus a liquid state. Textbook pp. 38–41 8 To help students gain a deeper understanding of the concepts learned, instruct them to carry out Activities 1 and 2. 9 Then, discuss with them the questions and conclusions based on their observations. Textbook pp. 42–43 10 To further introduce one of the properties of the state of matter, diffusion, ask the students if they understand what diffusion is and guide them to give examples of diffusion in their daily lives. 11 Explain that diffusion is the process of particles spreading from a region of higher concentration to a region of lower concentration. 12 Show the video clip at https://www.youtube.com/watch?v=KRLNDTmBFZY or provide the QR code for students to scan and view. This video will help them understand the concept of diffusion. Then, have them answer the question in ‘Think About It’. Textbook pp. 44–45 13 Tell the class that they will be observing and comparing the rate of diffusion in three states of matter. 14 Instruct them to carry out Experiment 1, starting with solid matter, then moving on to liquid matter and finally with gas matter. 15 Have them record their observations and compare the rate of diffusion in the three states of matter. 16 Ask students to describe the results they obtained and provide reasons for why they think diffusion rates vary in various states of matter. 17 Emphasise the effect of variables such as temperature, pressure and concentration on the rate of diffusion. Encourage students to brainstorm the real-world applications of the concept of diffusion in different states of matter, such as in manufacturing. Textbook pp. 46–48 18 As a class, review the properties of each state of matter. Allow them to refer to the charts created and complete the charts if necessary. Based on the charts, ask students whether matter can change from ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 21 © Praxis Publishing Singapore Pte. Ltd. one form to another, and how. Guide the students until they understand the fact that matter changes states due to the transfer of heat energy and changes in energy of molecules. The processes involved melting, freezing, boiling and condensation. 19 Begin by asking students if they have ever seen the transformation of water from a solid state (ice) to a liquid state (water), and then to a gaseous state (steam). Ask whether they are aware of why this occurs. 20 Define the terms melting, freezing, boiling, evaporation, condensation, sublimation as well as deposition. Introduce the concept of heat energy and discuss the relationship between temperature and state changes. Textbook pp. 48–52 21 Have students carry out Experiment 2. Start with the melting of ice, then followed by the boiling of water. 22 Ask students to record their results from the experiment, and then facilitate a class discussion on the questions related to the experiment. 23 Introduce the concept of conservation of mass during changes in the states of matter and allow students to conduct Experiment 3, which has three parts to prove the concept. 24 Review the changes of state of matter, the conditions that cause them and the energy changes that occur. Textbook pp. 52–54 25 Introduce real-world scenarios in which the changes of state of matter are important, such as cooking and industrial processes. In addition, explain to the students how the different states of matter occur naturally in cycles, such as the water cycle. Direct the students to scan the QR code in the ‘Resource’ section to gain a better understanding. 26 Encourage students to think how their understanding of states of matter may be applied in the actual world by having them work in groups. 27 Let them research and present on a specific real-world scenario involving state changes, including the conditions that cause the change of state of matter and the energy changes that occur. They need to talk about the effects of their scenario on society and the environment. Assessment and Evaluation 1 Students’ understanding of the three states of matter can be assessed through their participation in class discussions and activities. 2 Assess students’ understanding of the concepts learned, as well as their scientific and critical thinking skills, attitudes and values, by observing their participation during Experiments 1 to 3. 3 Students’ research, critical thinking and presentation skills can be assessed through their completion of the group activity on the real-world scenario involving state changes and the effects of the scenario on society and the environment. 4 Have students complete Exercises 1–10 Workbook pp. 17–24 . They can get additional information about the water cycle via the given QR code. 5 Provide feedback to students on their performance, highlighting areas where they have achieved and areas where they need to improve. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 22 © Praxis Publishing Singapore Pte. Ltd. Closure To summarise the important ideas and concepts taught in the lesson, consider using the key points provided through strategies such as a class discussion, a summary statement, a quiz, a visual organiser or a reflective writing assignment. Allow students to ask any additional questions for clarification or clear up any doubts. Three States of Matter 1 Matter can exist in three main states: solid, liquid and gas. 2 A substance’s state of matter is determined by its temperature and pressure. For example, water can exist as a solid (ice), liquid (water) or gas (steam) depending on temperature and pressure. 3 Particles in a solid are closely packed and have a fixed shape and volume. Particles in a liquid are loosely packed and have a fixed volume but not a fixed shape. Particles in a gas are far apart and have neither a fixed shape nor a fixed volume. Diffusion Rate in Three States of Matter 4 Diffusion is the movement of particles from a high concentration area to a low concentration area. This occurs in any of the three states of matter. 5 Diffusion in solids occurs at a much slower rate than in liquids and gases, due to the tightly packed arrangement of particles. 6 Diffusion in gases occurs at the fastest rate compared to solids and liquids, due to the high amount of kinetic energy and the large distances between particles. 7 Diffusion plays an important role in many natural and industrial processes, including the transfer of oxygen and carbon dioxide in the body, and chemical diffusion in environmental systems. Changes of State 8 A change of state is the process of changing from one state of matter to another. Melting, freezing, evaporation, condensation, sublimation and deposition are the six types of state changes. 9 Energy is either absorbed or released during a state change. When ice melts, it absorbs energy, whereas when water freezes, it releases energy. 10 Kinetic theory, which states that all particles are in constant motion and that the rate of motion depends on their temperature, can explain the movement of particles in matter. 11 Understanding the states of matter is important in many scientific fields, particularly in industries such as the manufacturing of foods and drinks. Extension / Follow-up Activities Role of Carbon Dioxide in Climate Change 1 Ask the students if they know about climate change and its impact on the environment. 2 Explain briefly the concept of climate change and show them a video that explains the role of carbon dioxide in climate change. 3 Have students share their thoughts and ask questions after watching the video. 4 Show the slide of water cycle and help students to recall the process of evaporation and condensation. 5 Discuss the impacts of carbon dioxide emissions on the water cycle, such as rising surface temperature and melting glaciers and polar ice caps. 6 Divide students into groups. Assign each group a specific source of carbon dioxide emissions, such as transportation, industry and deforestation. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 23 © Praxis Publishing Singapore Pte. Ltd. 7 Get students to think of plans to reduce carbon dioxide emissions in order to lessen its impact on the water cycle. Let them research the sources and effects of their assigned emissions on the state of matter, including the water cycle. 8 Lead a group discussion about the impact of carbon dioxide emissions on states of matter, and methods to reduce emissions and reduce the effects of climate change. Have each group to share their findings and express their opinions. Textbook Answers Activity 1 p. 38 Observation: Activity A: The air in balloon Q escapes and the metre rule tilts to the left. Activity B: Student’s answer Discussion: 1 Matter is a substance that has mass and occupies space. 2 (a) Air has mass and occupies space. (b) Green beans have mass and occupy space. 3 Pencil, water bottle, computer and lamp (or any other objects) 4 Air occupies space in the bicycle tyre. 5 (a) and (c) 6 Because the mass of air is too small. Conclusion: Matter has mass and occupy space. Activity 2 p. 40 Observation: Section A: Solid, orderly, Vibrate, low Section B: Liquid, Loose, randomly, Moderate Section C: Gas, Very loose, quickly, High Discussion: 1 (a) Particles (b) Matter is made up of tiny and discrete particles. 2 (a) The syringe filled with air. (b) The syringe filled with air is easy to be compressed because the air particles are arranged very far apart from one another. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 24 © Praxis Publishing Singapore Pte. Ltd. 3 (a) liquid (b) solid (c) solid (d) gas Conclusion: Particles in solid, liquid and gaseous states have different arrangement and movement. Think About It p. 43 Potassium permanganate is a chemical used in the treatment of skin infection/burns. Experiment 1 p. 44 Hypothesis: The rate of diffusion increases from solids, liquids to gases. Manipulated variable: Type of diffusion medium (solid, liquid and gas) Responding variable: Rate of diffusion Observation: A: blue, slowly B: blue, quickly C: very quickly Discussion: 1 (a) slow, small (b) fast, big (c) very fast, very big 2 Diffusion is the movement of particles from a high concentration region to a low concentration region. 3 (a) increases (b) The particles in copper(II) sulphate crystal moves more rapidly when the temperature increases. Conclusion: The rate of diffusion increases from solids, liquids to gases. The hypothesis is accepted. Experiment 2 p. 48 A Manipulated variable: Time when temperature is recorded Responding variable: Temperature B Manipulated variable: Time when temperature is recorded Responding variable: Temperature Discussion: 1 (b) The ice cubes changed to water as the temperature remained constant. (c) 0°C 2 (b) The water changed to vapour as the temperature remained constant. (c) 100°C 3 The temperature remains constant because the heat absorbed is used to overcome the force of attraction between the particles. 4 Conclusion: Temperature is constant during the changes of state. The hypothesis is accepted. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 25 © Praxis Publishing Singapore Pte. Ltd. Experiment 3 p. 50 A Manipulated variable: Solid and liquid states of matter Responding variable: Mass of water in solid and liquid states B Manipulated variable: Change of state of sugar Responding variable: Mass of sugar C Manipulated variable: Size of metal ball Responding variable: Mass of the metal ball Discussion: 1 (a) Remained the same (b) The mass of matter remains the same because the quantity of particles in the matter remains the same during a change of state. 2 (a) & (b) The mass remains the same because the quantity of particles remains the same; only the arrangement of particles is different. (c) The mass changes because a new product is formed. The quantity of particles is different before and after burning the iron powder. Conclusion: Mass remains constant during the changes of state. The hypothesis is accepted. Lesson 2.2 Physical and Chemical Changes Learning Outcomes • Explain the differences between physical and chemical changes • Identify the physical properties of matter that are involved in physical changes • Identify the indicators that show signs of chemical change • Analyse the physical and chemical changes in various everyday situations Key Understanding Physical and chemical changes are basic concepts that describe how matter can be changed. Physical changes involve a change in matter’s physical properties, such as density or shape, without changing the substance’s chemical composition. On the other hand, chemical changes involve a change in the chemical composition of matter, such as the formation of new substances via chemical reactions. Temperature, pressure and energy may change as a result of physical and chemical changes. Physical changes are generally reversible, whereas chemical changes are usually irreversible. Cooking, digestion and combustion are a few examples of processes that involve physical and chemical changes. Induction 1 Introduce the topic of physical and chemical changes, and explain the learning outcomes of the lesson. 2 Ask students if they have any experience with physical and chemical changes, have them share their thoughts. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 26 © Praxis Publishing Singapore Pte. Ltd. Teaching and Learning Activities Textbook p. 54 1 Provide examples of physical and chemical characteristics of a substance to the students. 2 Define physical changes and provide examples such as state changes (e.g., melting, boiling). 3 Ask the students to give other examples of physical changes and discuss the properties of matter involved in these changes. Get them to answer the question in ‘Think About It’. Textbook pp. 55–56 4 Provide examples such as burning, corrosion and cooking. Allow students to brainstorm how these processes are different from melting and boiling. Encourage students to explain the difference between physical and chemical changes. 5 Guide students to identify the indicators of chemical changes, such as changes in colour or temperature, the production of bubbles or odours, or formation of a new product. 6 Have the students give other examples of chemical changes and answer the question in ‘Think About It’. 7 Discuss the differences between physical and chemical changes. For example, the reversibility of physical changes and the formation of new substances in chemical changes. 8 Students compare and contrast physical and chemical changes, and discuss the properties of matter involved in these changes. Let them list out the differences in class as a group and discuss the importance of physical and chemical changes in everyday life. Textbook pp. 56–57 9 To further enhance students’ understanding of the discussed contents, let students carry out Activity 3 which will enable them to differentiate between physical and chemical changes in matter. 10 Get them to record the observations, then discuss the questions and conclusion. Assessment and Evaluation 1 Assess students’ critical thinking and problem-solving skills in Extension / Follow-up Activities and by observing their participation in class discussions on physical and chemical changes, encouraging them to think deeply about the differences between these changes and their importance in everyday life. 2 Evaluate students’ understanding of the concepts learned, as well as their scientific skills, attitudes and values, by observing their participation during Activity 3. Review their participation in answering the discussion questions in the activity and drawing a conclusion. 3 Have students complete Exercises 1–3 Workbook pp. 24–27 to check their understanding. 4 Provide feedback to students on their performance, highlighting areas where they have achieved and areas where they need to improve. Closure To summarise the important ideas and concepts taught in the lesson, consider using the key points provided through strategies such as a class discussion, a summary statement, a quiz, a visual organiser or a reflective writing assignment. Allow students to ask any additional questions for clarification or clear up any doubts. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 27 © Praxis Publishing Singapore Pte. Ltd. Physical Changes 1 Physical changes involve a change in the look or form of a substance, but its chemical composition stays unchanged. Changes in state (such as melting or boiling), changes in shape or size (such as cutting or crushing), and changes in colour or texture are all examples of physical changes. 2 Physical changes are generally reversible, which means that the original material can be regained after the change. If a piece of ice is melted, we can reverse the process by freezing the ice in liquid form. 3 No new substances are formed or destroyed during physical changes. They involve rearranging the molecules or particles within the substance. 4 Physical changes can be distinguished from chemical changes, which involve a change in the chemical composition of a substance. Chemical Changes 5 Chemical changes result in the production of new substances having chemical properties that differ from the original substance. 6 Chemical changes commonly involve the breaking and formation of chemical bonds between atoms and molecules. 7 Chemical changes can be detected by the presence of signs such as colour changes, temperature changes, gas production or precipitate formation. 8 Chemical changes are usually irreversible, which means that the original material cannot be regained physically. 9 Chemical changes can occur spontaneously, but they often require the use of energy, such as heat, light or electricity. 10 Many natural and industrial processes, such as photosynthesis, digestion and combustion rely on chemical changes. Extension / Follow-up Activities Plan your own investigation or let students carry out the following investigation in small groups to deepen their understanding of chemical changes. Chemical Reaction Investigation Option 1: Engage students in a hands-on activity that utilises commonly available home materials, such as baking soda and vinegar, to demonstrate chemical changes and their effects on matter. They can mix baking soda and vinegar to produce carbon dioxide gas or mix iron filings and sulphur to produce a new substance. Let students record their observations, such as changes in colour, temperature and the production of gas to identify the presence of a chemical reaction. Option 2: Students can mimic chemical reactions and identify the products produced by using online virtual laboratory such as PhET Interactive Simulations. They can also experiment with the reaction parameters, such as temperature, concentration and catalysts, to see how these affect the reaction rate and the products produced. Textbook Answers Think About It p. 54 The melting of the candle is a physical change as no new product is formed. When the hot candle wax is cooled, it turns back to solid wax. ©Praxis Publishing_Focus On Science

Teacher’s Guide Focus-on Science Grade 7 28 © Praxis Publishing Singapore Pte. Ltd. When a candle burns, it reacts with oxygen in the air to produce carbon dioxide and water vapour. Heat and light are released. So, the burning of the candle is a chemical change. Think About It p. 56 Physical changes: breaking eggs, grating carrots, paper tearing Chemical changes: fermentation of milk into yogurt, rotting of vegetables, bread moulding Activity 3 p. 56 Observation: A: dissolves, physical change B: rusts, chemical change Discussion: 1 A: change of state, from solid to liquid, no new product formed B: new product formed 2 air, water 3 (a) physical change (b) chemical change (c) chemical change (d) physical change (e) physical change (f) physical change (g) chemical change Conclusion: Physical change does not result in the formation of new products whereas chemical change results in the formation of new products. Lesson 2.3 Density Learning Outcomes • Define density and describe how it is calculated • Identify whether an object will float or sink in a given fluid based on its density • Explain why some objects float and some objects sink in fluids • Apply the knowledge of density to real-world situations Key Understanding Density is a key concept that is related to whether an object will float or sink in a fluid. Density of a substance determines how much mass is contained within a certain volume of the substance. This suggests that, given the same volume, substances containing tightly packed particles have a higher density than those containing loosely packed particles. Understanding the connection between mass and volume is critical to calculating density, which is measured in gram per cubic centimetre or kilogram per cubic metre units. A key idea is that whether an object floats or sinks is determined by its density when compared to the fluid in which it is placed. If the object’s density is less than that of the fluid, it will float. It will sink if its density is larger. This knowledge can be used by students to understand how ships float and submarines ©Praxis Publishing_Focus On Science