Chapter 1: Stimuli and Response TOPIC SUBTOPIC EXPLANATION 1.1 Human Nervous System Structure of Human Nervous System Human Nervous System consists of: a) Central nervous system - brain, spinal cord b) Peripheral nervous system - cranial nerve(12pairs), spinal nerve(31pairs) Function of Human Nervous System - controls & coordinates organs & body parts - detects stimuli - send information in the form of impulses - interprets impulses - produces appropriate responses Voluntary and Involuntary Actions Voluntary Actions - conscious actions & conducted under one’s will - controlled by brain - writing, reading, singing, eating, walking, etc. Involuntary Actions - occur immediately w/o conscious control or prior thoughts - can be classified into two: ❖ Involving medulla oblongata - heartbeat, breathing, peristalsis, secretion of saliva ❖ Involving spinal cord (reflex actions) - sneezing when dust enters the nose Importance of Human Nervous System in Daily Life - function to control and coordinate organs and body parts to carry out processes in the body and daily activities 1.2 Stimuli and Responses in Human Eye Structure of the Eye a) retina has 2 photoreceptors: rod cells & cone cells b) rod cells - sensitive to different light intensities c) cone cells - sensitive to the colours of lights
Ear Structure of the Ear Function of the parts of the human ear Nose Parts of the Human Nose Structure of the Nose - sensory organ of smell - smells are chemical substances present in the air - approx.. 10 million sensory cells for smell are located at the roof of nasal cavity Function of Sensory Cells for Smell - tiny and covered with a layer of mucus - chemical substances dissolve in the mucus and stimulate the cells to produce nerve impulse - the impulses are then sent to the brain to be interpreted to determine the type of smell
Tongue Parts of the Human Tongue Structure of the Tongue - sensory organ for taste - have tiny nodules called papillae - surface of papillae covered with hundreds of taste buds - each taste bud contains 10 to 50 taste receptors - can detect 5 basic taste: sweet, salty, sour, bitter, umami Function of Taste Buds - when food is chewed, chemical substance in food dissolved in saliva - dissolved chemical substance will diffuse into the taste buds through their pores & stimulate the taste receptors in them to produce nerve impulses - nerve impulses then sent to the brain to be interpreted as 5 tastes Skin Parts of the Human Skin - largest sensory organ - made up of thin outer layer(epidermis) & an inner layer(dermis) - has 5 types of receptors: cold, pain, heat, touch, pressure - when receptor is stimulated, nerve impulses are produced and sent through the nervous system to the brain to be interpreted
Mechanism of Hearing Mechanism of Sight Sensitivity of the Skin on Different Parts of the Body towards Stimuli The sensitivity of skin towards stimuli depends on the number of receptors and the thickness of the skin epidermis. Example: - the tip of finger is very sensitive towards stimuli because there are a large number of touch receptors and the epidermis is thin. Sensitivity of the Tongue towards Different Taste Stimuli Different areas of the tongue have different sensitivities towards specific taste.
Limitation of Sight - the limitation in the ability of the eye to see objects. - we can’t see very tiny objects and very distant objects. - limitation of sight include: a) Optical Illusions - occurs when an object is seen differs from its actual state. - occurs because brain is unable to accurately interpret the object seen by the eye due to distractions around the object. b) Blind Spot - an obstruction of the visual field Example of Devices to Overcome Limitations of Sight: - binoculars - ultrasound machine - microscope - x-ray machine Defects of Sight and Ways to Correct Them Defects of sight How it is corrected Short-sightedness - inability to see distant object - blurry, because image is focused in front of retina - caused by eye lens too thick or eyeball too long - using concave lens Long-sightedness - inability to see near object - blurry, because image is focused behind the retina - caused by eye lens too thin or eyeball too short - using convex lens Astigmastism - seeing part of an object clearer than the rest of it - caused by uneven curvature of the cornea or eye lens - using cylindrical lenses
Limitations of Hearing - limitations in the ability of the ear to hear sound (20 Hz - 20 000 Hz) - frequency range of hearing of person is different - when person get older, frequency range gets narrower as eardrum becomes less elastic Example of Equipment used to Overcome Limitations of Hearing: - stethoscope - loudspeaker Defects of Hearing and Ways to Correct Them - occur when the sense of hearing doesn’t function well - due to infection by microorganism, injury, ageing process a) Damages to outer ear and middle ear (easily corrected) - clearing foreign objects in the ear canal - correcting punctured eardrum and damaged ossicles through medicine or surgery b) Damaged to inner ear (difficult to correct) - damaged cochlea can be corrected using cochlea implant - damaged auditory nerve cannot be corrected with medicine or surgery Example of Device to Help Patient with Hearing Problem - hearing aid 1.3 Stimuli and Response in Plants Tropism - directional response of plants to stimuli(light, water, gravity, touch) - certain parts of plants will grow towards or grow away fr. Stimulus - grow towards a stimulus → positive tropism - grow away from a stimulus → negative tropism - 4 types of tropism: a) Phototropism - response towards light - shoots of plants shows positive tropism (to obtain sunlight) b) Hydrotropism - response towards water - roots of plants shows positive tropism (to obtain water) c) Geotropism - response towards gravity - roots of plants shows positive tropism (to stabilize position) - shoots of plants shows negative tropism (to obtain sunlight) d) Thigmotropism - response towards touch - tendrils or twining stem shows positive tropism (cling on object to obtain sunlight and stabilize position) - roots show negative tropism (avoid object that obstruct water) Nastic Movement - response towards touch but doesn’t depend on the direction of stimulus - occurs more rapidly than tropism Example: Mimosa sp. responds to touch by folding its leaves inwards when touched (defence against enemies and strong wind)
1.4 Importance of Responses to Stimuli in Animals Stereoscopic and Monocular Vision Stereoscopic vision Monocular vision Eyes located in front of head. Eyes located at sides of head. Narrow vision field. Wide vision field. Vision field overlapped and produce vision in 3D. Vision field don’t overlap. Overlap slightly. 3D images is formed, allow the distance, size and depth of object estimated accurately. 2D images formed, prevent the distance, size and depth of object estimated accurately. Helps animals to hunt. Helps animals detect enemies. E.g. human and most predators E.g. most prey Stereophonic Hearing - hearing using both ear - allows us to determine the direction of the sound accurately Importance of Stereophonic Hearing - to determine location of a source of sound - helps predators determine the location of their prey - helps prey determine location of their predator & escape fr. them Hearing Frequencies of Animals Sea lion 450 – 50 000 Hz Dolphin 40 – 100 000 Hz Elephant 16 – 12 000 Hz Dog 67 – 45 000 Hz Bat 2 000 – 110 000 Hz Rat 200 – 80 000 Hz Sensory Organs Ensure the Survival of Animals on Earth
Chapter 2: Respiration TOPIC SUBTOPIC EXPLANATION 2.1 Human Respiratory System Human Respiratory System Breathing Mechanism Inhalation - intercostal muscle contract and pull rib cage upwards & outwards - diaphragm muscle contract and pull it to descend and become flat - thoracic cavity bigger and air pressure in thoracic cavity decrease - high air pressure outside forces air to enter the lungs Exhalation - intercostal muscle relax and rib cage moves downwards & inwards - diaphragm muscle relax and curved upwards - thoracic cavity smaller and air pressure in thoracic cavity increase - high air pressure inside the lungs pushes the air out Epiglottis: Percentage/Concentration Inhaled air Exhaled air Oxygen Higher Lower Carbon dioxide Lower Higher
2.2 Movement and Exchange of Gases in the Human Body Movement and Exchange of Oxygen and Carbon Dioxide in the Human Body ① - inhaled air has high concentration of O2 compared to blood. - O2 will diffuse through the wall of alveolus into the walls of capillaries and into the blood ② - in RBC, dark red-coloured Hb will combine with O2 to form O2Hb (unstable compound, bright red coloured) ③ - blood with O2Hb is transported from the lungs to the heart and pumped to other body parts ④ - when blood reached area with low O2 concentration, O2Hb will decompose to release O2 and change back to Hb: Oxyhaemoglobin → haemoglobin + oxygen ⑤ - in body cells, O2 oxidises C6H12O6 into CO2, H2O and energy Glucose + oxygen → carbon dioxide + water + energy ⑥ - CO2 released by the cells diffuses into BC and is transported to the alveolus to be removed during exhalation Importance of the Adaptations of the Alveolar Structure a) Thickness of the walls of alveolus and blood capillaries b) Moist wall of alveolus c) Surface area of alveolus d) Network of capillaries covering the alveolus 2.3 Health of Human Respiratory System Substances that are Harmful to the Human Respiratory System a) Cigarette Tar - kills cells in air passage(thorax, pharynx, larynx, epiglottis, etc.) Harmful Substances Found in Cigarette Smoke:
b) Carbon Monoxide - found in cigarette smoke & exhausts gases - colourless & odourless - when diffuses into blood capillaries, it will combine with Hb Carbon monoxide + haemoglobin → carboxyharmoglobin - causes a shortage of O2Hb in blood that transport O2 in body c) Sulphur Dioxide - produced by combustion of coal from power stations - colourless gas with pungent smell - irritates air passage, causes cough, difficulty breathing, bronchitis and lung cancer d) Nitrogen Dioxide - produced by combustion of fuel such as petrol & diesel - brown-coloured gas with pungent smell - irritates air passage, causes cough, difficulty breathing & asthma e) Haze, Dust and Pollen - produced by smoke from vehicles, open burning and forest fire - solid particles, fine, light and suspended in the air - pollen released from anthers into the air is carried by wind - irritate respiratory sytem, cause asthma Respiratory Disease and their Symptoms a) Asthma Cause : triggered by presence of dust, pollen, haze, smoke Symptoms : shortness of breath, wheezing, coughing b) Bronchitis Condition : inflammation of the bronchus Cause : tar and irritants in cigarette smoke Symptoms : shortness of breath, persistent coughing, insomnia c) Emphysema Condition : alveoli in the lungs are damaged Cause : irritants in cigarette smoke Symptoms : shortness of breath, pain when breathing, feeling tired from doing even light task Treatment : cannot be cured, but symptoms can be controlled d) Lung Cancer Cause : cancer causing chemical substances, carcinogens Symptoms : persistent coughing, bloody phlegm, pain breathing Effects of Smoking on the Lungs - not only harmful to smokers, also to other people in vignity Passive Smoker - person who doesn’t smoke but inhales cigarette smoke. 2.4 Adaptations in Respiratory System How the Respiratory System Adapts in Different Surroundings Three features to ensure an efficient gaseous exchange: - Moist surface of respiratory structure - Thin reaspiratory structure - Large surface area of respiratory structure Moist Outer Skin - skin of frogs is thin and very permeable to gas - moist, covered with layer of mucus, respiratory gas diffuse easily - under the skin, dense network of blood capillaries, to increase the diffusion rate of gases between skin and blood capillaries
Gills - made up of 2 rows of fine filaments that have many thin & flat projections called lamellae - no. of filaments and lamellae produces a large surface area to facilitate gaseous exchange - gills surrounded by water, respiratory gases diffuse & disssolve easy Trachea - air enters/leaves the trachea through pores called spiracles - opening/closing of spiracles controlled by valves - trachea divided into fine branches called tracheoles - tracheoles have thin and moist walls, increase gas exchange - large no. of tracheoles provides large surface area - some have air sacs in trachea system (grasshopper) - air sacs filled with air, increase rate of exchange of respiratory gas 2.5 Gaseous Exchange in Plants Mechanism of Gaseous Exchange in Plants - gaseous exchange through leaves, stems and root - these 3 parts provide a large surface area for gaseous exchange
Diffusion of Carbon Dioxide ① - when CO2 is used in photosynthesis, concentration of CO2 in cell is lower than CO2 in air space between cells - difference in concentrations allows dissolve CO2 in moist surface of cells to diffuse from air space between the cells into the cell ② - concentration of CO2 in air space between the cells become lower than CO2 outside stoma - difference in concentrations allows diffusion of CO2 from air space between the cells into the atmosphere through stoma Stomatal Pore and Guard Cells - stoma is made up of a stomatal pore bounded by 2 guard cells - guard cells contain chloroplasts to carry out photosynthesis - open during there is light (photosynthesis) - close during dark or when plant loses a lot of water/hot day Process of Osmosis Affects the Stoma Concept of Osmosis - movement of water molecules from a region of high concentration of water molecules(low solutes) to low concentration of water molecules(high solutes) through a semipermeable membrane - membrane is permeable to water but not to some solutes (sucrose)
Process of Osmosis in Guard Cells - guard cells carry out photosynthesis to produce glucose - concentration of glucose in guard cells increase, causes water from surrounding cells to diffuse into the guard cells through osmosis - guard cells become turgid and curved - at night/hot day, water diffuse out of guard cells through osmosis - guard cells become flaccid and straight Effects of Osmosis on Stoma - during the day, water diffuses into the guard cells through osmosis - causes both guard cells to curve and open the stoma - at night/hot day, water diffuses out of guard cells through osmosis - causes both guard cells to become straight and close the stoma Open stoma Closed stoma Importance of Unpolluted Environment for the Survival of Plants Effects of Haze and Dust on the Survival of Plants - reducing sunlight from reaching the plants - reducing the rate of photosynthesis - prevent gaseous exchange between palnts and their surroundings Effects of Acidic Gases in the Air on the Survival of Plants - kills plants cells - causes soil to be acidic and unfertile - reduce agricultural produce and cause food shortage Preventive measures against effects of pollutions: - ban open burning (Indonesia & Malaysia) - limit the number of motor vehicles on the road (Beijing, China) - encourage the use of alternative energy such as solar power
Chapter 3: Transportation TOPIC SUBTOPIC EXPLANATION 3.1 Transport System in Organisms Need for Transport System in Organisms - to carry substances needed by cells into organisms and eliminates waste products from organisms to the outside surroundings Transport System in Simple Organisms - unicellular organisms - do not have specialised transport system - substances needed enter directly into the cells via diffusion - wastes eliminated via diffusion through cell membrane - e.g. Amoeba sp., Paramecium sp., Euglena sp. Transport System in Complex Organisms - humans, vertebrates, multicellular plants - have a specialised transport system - exchange of substances needed and waste elimination process occur slowly and not comprehensively as complex organism is large Importance of the Function of Transport System in Organisms - carries substances needed by cells such as oxygen, nutrients that are used to produce energy through cellular respiration - carries substances needed by plant cells such as mineral salts, nutrients and product of photosynthesis - eliminates toxic waste from the cells to the external environment 3.2 Blood Circulatory System Blood Circulatory System in Vertebrates Similarities in the Blood Circulatory System among Vertebrates - made up of system that allows blood flows continuously in blood vessel to all parts of the body through heart Difference in the Blood Circulatory System among Vertebrates a) Fish b) Amphibians c) Reptiles d) Mammals & birds
Blood Circulatory System in Humans - circulation of blood pumped from heart to all parts of the body an specialised vessels-arteries, capillaries and veins Structure and Functions of the Human Heart Parts Characteristic/Function Right atrium - has thin muscular wall - contains deoxygenated blood except fr. lungs through superior and inferior vena cava - when contracts, blood flow into right ventricle Triscupid valve - allows blood to flow in one direction from right atrium to the right ventricle Right ventricle - has thick muscular wall - when contracts, deoxygenated blood is forced to flow out into the pulmonary artery to be carried to the lungs Semilunar valves - located at pulmonary artery and aorta - ensure blood to flow in one direction and not back into the ventricles Left atrium - has thin muscular wall - contains oxygenated blood from lungs that enters through pulmonary vein - when contracts, blood flow into left ventricle Biscupid valve - allows blood to flow in one direction from left atrium into the left ventricle Left ventricle - has the thickest muscular wall - when contracts, oxygenated blood is forced to flow out into the aorta to be carried to all body parts except the lung Septum - muscular wall that seperates the left and right side of the lungs - prevents oxygenated blood and deoxygenated blood from mixing
Structure and Functions of Main Blood Vessels Type Aspect Vein Capillary Artery Structure - thin wall - less muscular - less elastic wall facilitate low bp - has valves - large lumen - thinnest (1cell) - no muscles - no elastic wall - no valves - smallest lumen - thick - muscular - a lot of elastic tissues to w/s high bp - no valves - small lumen Functions - transports deoxy. blood to heart from the body except lungs - pulmonary vein transport oxy. blood fr. lungs to the heart - allows the exchange of gases, food & waste between blood and cells via diffusion through thin wall of capillary - transport oxy. blood fr. heart to body except lungs - pulmonary artery transport deoxy. blood fr. heart to lungs Circulation of blood - slow blood flow under low bp - no pulse - slow blood flow decreasing bp - no pulse - rapid bloodflow under high bp - pulse detected ‘Double’ Blood Circulatory System - human & other mammals have ‘double’ blood circulatory system - pulmonary circulatory system & systemic circulatory system
Heartbeat Diastole Systole - produce ‘dub’ sound - closure of semilunar valves - relaxation of ventricles occurs - pressure reading of blood filling the heart - diastolic preassure reading - produce ‘lub’ sound - closure of triscupid & biscupid - contraction of ventricles occur - preassure reading of blood flowing out of the heart - systolic pressure reading Measurement of Blood Pressure - measured using sphygmomanometer - written as systolic/diastolic mmHg (e.g. 120/75 mmHg) Pulse Rate - produced by contraction and relaxation of muscular artery wall Factors that Influence the Pulse Rate a) Physical activity c) Age b) Gender d) Body health 3.3 Human Blood Components and Constituents of Human Blood - a type of mixture - can be separated into 2 components (yellow & red liquid) - separated using centrifugal method Components of Blood - consists of a suspension of RBC(45%), WBC & platelets(<1%), blood plasma(55%) - blood plasma, made of ± 90% water and 10% dissolved substances Human Blood Group Antigens on Red Blood Cells Blood group A Blood group B - only have the A antigen - only have the B antigen Blood group AB Blood group O - have both A & B antigens - do not have A or B antigens
3.4 Transport System in Plants Antibodies in Blood Plasma - blood plasma contains antibodies - types of antibodies: Anti-A and Anti-B Type of blood Types of antigens (on surface of RBC) Types of antibodies (in blood plasma) A A Anti-B B B Anti-A AB A and B - O - Anti-A and Anti-B ❖ person with Anti-A antibodies cannot receives A & AB blood ❖ person with Anti-B antibodies cannot receives B & AB blood ❖ person with AB blood can receive all types of blood ❖ person with O blood cannot receive other types of blood Compatibility of Blood Groups of Donors and Recipients Blood group (Donor) Blood group (recipient) A B AB O A ✓ ✓ B ✓ ✓ AB ✓ O ✓ ✓ ✓ ✓ Importance Of Blood Donation - to save lives - required for surgery, accident victims, etc. - treat patients with leukaemia, haemophilia, etc. Transpiration - process of water loss in the form of water vapour from leaves to the air through evaporation Cross Section of a Leaf - epidermis is made up of single layer of epidermal cells covering upper and lower epidermis - epidermal cells secrete a waxy cuticle, covers outer surface of leaf (to reduce water loss during transpiration)
Function of Stoma during Transpiration - water lost during transpiration occurs through the stomatal pores - photosynthesis(day), stoma is open (causes plant to lose water) - stoma will also close to reduce water loss during transpiration Exudation (Guttation) - water loss from plants in liquid form through hydathodes that are always open at the edge of the leaves - usually occurs at night or when the air humidity is high Rate of Transpiration Factors affecting transpiration: - no. of stomata - temperature - light intensity - movement of air - air humidity Structures and Functions of the Components in Vascular Bundle of Plants - transpiration helps transportation of water&mineral salts in plants - during transpiration, water, and dissolved mineral salts diffuse into plants through roots to the stem and leaves - Xylem : transport water and mineral salts from roots to leaves to carry out photosynthesis & replace water lost during transpiration - Phloem : transport sucrose produced by leaves during photosynthesis to other parts of the plant 3.5 Blood Circulatory System in Animals and Transport System in Plants Similarities and Differences between Blood Circulatory System in Animals and Transport System in Plants Similarities Blood circulatory system in animals Transport system in plants - Both are transport system - Both transport water, nutrients and dissloved substances - Both exist in complex organism Blood circulatory system in animals Differences Transport system in plants - tubular system w/ heart and valves Structure - system of vessels w/o pump/valve - 3 types of vessels: - artery - capillary - vein Types of transport vessels - 2 types of vessels: - xylem - phloem - 3 types of vessels are connected to form 1 continuous vessel Connection between transport vessels - xylem and phloem are not connected and are two separate vessels
Chapter 4: Reactivity of Metals TOPIC SUBTOPIC EXPLANATION 4.1 Variety of Minerals Various Forms of Minerals in Earth’s Crust Minerals - solid elements/compounds present naturally with definite crystalline structures and chemical compositions - contained in rocks found in Earth’s crust Examples of elements : gold and silver Examples of compounds : bauxite, hematite, galena, cassiterite Common name Systematic name Combination of elements Hematite Iron(III) oxide Iron, oxygen Cassiterite Tin(IV) oxide Tin, oxygen Quartz Silicon oxide Silicon, oxygen Bauxite (aluminium) Aluminium oxide Aluminium, oxygen Galena (lead ore) Lead(II) sulphide Lead, sulphur Pyrite Iron(II) sulphide Iron, sulphur Calcite Calcium carbonate Calcium, carbon, O2 Natural Compounds are the Combination of Several Elements How to show that a natural compound is a combination of several element? ① What gas is tested? →Carbon dioxide ② How the test is carried out? →Flow the gas through limewater If water cloudy, gas is CO2 Calcium carbonate + hydrochloric acid → calcium chloride + carbon dioxide + water heated Calcium carbonate → calcium oxide + carbon dioxide ③ 3 elements combine in calcium carbonate→ calcium, carbon, O2 4.2 Reactivity Series of Metals Reactions of Metals 1. vigorous reaction - magnesium(Mg) and oxygen(O2) 2. less vigorous reaction - iron(Fe) and oxygen(O2) Constructing Reactivity Series of Metals - different metals have different reactivity towards oxygen Au – gold Zn – zinc Ag – silver Al – aluminium Hg – mercury Mg – magnesium Cu – copper Ca – calcium Pb – lead Na – sodium Sn – tin K – potassium Fe – iron
Reaction of heating metals (Mg, Al, Zn, Fe & Pb) with oxygen: Metals Observation Metal burns very quickly and brightly Metal burns quickly and brightly Metal burns slowly Metal glows brightly Metal glows dimly Mg ✓ Al ✓ Zn ✓ Fe ✓ Pb ✓ Magnesium + oxygen → magnesium oxide Aluminium + oxygen → aluminium oxide Zinc + oxygen → zinc oxide Iron + oxygen → iron oxide Lead + oxygen → lead oxide Relationship between the vigour of the reactions and the reactivity of the metals towards oxygen ❖ The more reactive the metal toward oxygen, the more vigorous the reaction. Position of Carbon in the Reactivity Series of Metals Determining the position of carbon in the reacticity series of metals Mixture Observation Reactivity of carbon Zinc oxide & carbon grey solid is formed reactive to carbon Aluminium oxide & carbon no change not reactive to carbon Lead(II) oxide & carbon grey solid is formed reactive to carbon
Zinc oxide + carbon → zinc + carbon dioxide Aluminium oxide + carbon → no reaction Lead(II) oxide + carbon → lead + carbon dioxide ❖ If carbon can remove oxygen from a metal oxide, it means carbon is more reactive than the metal. ❖ If carbon cannot remove oxygen from a metal oxide, it means carbon is less reactive than the metal. Position of Hydrogen in the Reactivity Series of Metals Mixture Observation Inference Hydrogen and aluminium oxide - doesn’t glow - white Hydrogen doesn’t reduce Al2O3 Hydrogen and zinc oxide - doesn’t glow - yellow (hot) white (cooling) Hydrogen doesn’t reduce ZnO Hydrogen and iron(III) oxide - burns brightly - redbrown powder turns shiny grey - iron is produced - hydrogen reduces Fe2O3 to iron Hydrogen and lead(II) oxide - burns brightly - yellow powder turns shiny grey - lead is produced - hydrogen reduces PbO to lead Hydrogen and copper(II) oxide - burns very brightly - black powder turns brown - copper is produced - hydrogen reduces CuO to copper ❖ Hydrogen is less reactive than aluminium. ❖ Hydrogen is less reactive than zinc. ❖ Hydrogen is more reactive than iron. ❖ Hydrogen is more reactive than copper. ❖ Hydrogen is more reactive than lead. Conclusion on the Position of Carbon and Hydrogen in the Reactivity Series of Metals
4.3 Extraction of Metals from their Ores Extraction of Metals - process to obtain metals from their ore K Potassium Na Sodium Ca Calcium Mg Magnesium Al Aluminium C Carbon Zn Zinc H Hydrogen Fe Iron Sn Tin Pb Lead Cu Copper Hg Mercury Ag Silver Au Gold Process of Iron Extraction - carried out in a blast furnace ① Mixture of concentrated iron ore, coke and limestone are added ② A very hot air blast is pumped into the furnace through bottom ③ Reactions that occur in the furnace at high temperature: Production of Iron (i) Coke reacts with oxygen in the hot air. Carbon + oxygen → carbon dioxide (ii) CO2 reacts with remaining coke, produce carbon monoxide. Carbon dioxide + carbon → carbon monoxide (iii)Carbon monoxide & carbon reduces iron oxide into iron. Iron(III) oxide + carbon → iron + carbon dioxide Iron(III) oxide + carbon monoxide → iron + carbon dioxide Iron(II) oxide + carbon → iron + carbon dioxide Iron(II) oxide + carbon → iron + carbon dioxide Production of Slag (i) Limestone(calcium carbonate) decomposes to CaO & CO. Calcium carbonate → calcium oxide + carbon dioxide (ii) CaO reacts with impurities(sand/SiO2) in iron ore to form slag. Calcium oxide + silicon dioxide → calcium silicate Extraction through electrolysis of metallic compounds in molten form Extraction through reduction of metal oxides by carbon Extraction through direct heating of the compound Exist in the form of elements in Earth’s crust
④ At high temperature, (i) - iron produced will melt. - molten iron flows to bottom of furnace - tapped off and channelled to moulds and allowed to cool - solidified molten iron called as cast iron (ii) - slag produced will melt. - molten slag flows to bottom of furnace - molten slag will float, because less dense than molten iron - tapped off and used to make the base of buildings or roads Mining Issues in Malaysia - air pollution by gases released from blast furnace - air pollution due to burning of fuels - water pollution due to cleaning of ore - sound pollution from mining machinery - soil erosion due to mining of ore - usage of large amount of electrical energy - destruction of habitat due to construction of mines Chapter 5: Thermochemistry TOPIC SUBTOPIC EXPLANATION 5.1 Endothermic and Exothermic Reactions Endothermic and Exothermic Reactions Thermochemistry - study of heat change that occur when chemical reaction take place Endothermic reaction - heat is released into the surroundings - cause a rise in temperature Exothermic reaction - heat is absorbed into the surroundings - cause a drop in temperature Examples of Exothermic and Endothermic Reactions in Daily Life Example of exothermic reaction: - burning of paper - bomb explosion - respiration - neutralisation of acid with alkali Example of endothermic reaction: - photosynthesis - cake baking - extraction of iron from iron ore - dissolving ammonium salt in water
Chapter 6: Electricity and Magnetism TOPIC SUBTOPIC EXPLANATION 6.1 Generation of Electricity Various Energy Sources to Generate Electricity - 2 types of energy sources: renewable & non-renewable Renewable energy sources - can be replaced continually and will never deplete Examples: - hydro energy - wind energy - wave energy - biomass energy - solar energy - geothermal energy - tidal energy Non-renewable energy sources - cannot be replaced and will deplete Examples: - nuclear energy - natural gas - coal - petroleum Power stations in Malaysia Power stations Energy sources Bakun hydroelectric power station (Sarawak) Hydro energy Tuanku Jaafar power station (N. Sembilan) Natural gas Sultan Azlan Shah power station (Perak) Coal Gelugor power station (Pulau Pinang) Diesel TSH Bio-Energy Sdn. Bhd. (Sabah) Biomass Hybrid power station (Pulau Perhentian Kecil) Wind,Solar,Diesel Process of Generating Electricity - using a generator - when the crank is turned, a current(induced current) is produced and lights up the LED - 1831, a scientist named Michael Faraday conducted a series of investigations on generation of electricity using a magnetic field - electric current is produced by: a) Movement of the wire - causes the magnetic field lines to be cut - a wire/solenoid is moved rapidly through the magnetic poles - induced current is produced and flows through galvanometer - the pointer in galvanometer deflects b) Movement of the magnet - causes the magnetic field lines to be cut - a magnet is moved so the magnetic field lines are cut by wire/solenoid - induced current is produced and flows through galvanometer - the pointer in galvanometer deflects
Electricity Generated at Power Stations ① Using non-renewable energy sources (diesel, natural gas, coal) Mechanism Energy Change Chemical energy→Heat energy→Kinetic energy→Electrical energy ② Using solar energy Mechanism Energy Change Solar energy→Electrical energy ③ Hydroelectric power station Mechanism Energy Change Gravitational potential energy→Kinetic energy→Electrical energy ④ Using wind energy Mechanism Energy Change Kinetic energy→Electrical energy Burning of fuels Boiling water produces steam Steam rotates the turbine Electricity is produced Sunrays Solar panels convert light energy into electricity High dam stores water Water flows from high to low level Water flows rotates turbine Electricity is produced Moving of air/wind Wind moves blade Blades rotates turbine Electricity is produced
⑤ Using nuclear fuel Mechanism Energy Change Nuclear energy→Heat energy→Kinetic energy→Electrical energy ⑥ Using biomass Mechanism Energy Change Chemical energy→Heat energy→Kinetic energy→Electrical energy Direct Current and Alternating Current Direct Current (d.c.) - electric current that flows in one direction only - e.g. torchlight, calculator (devices), batteries, accumulator (source) Alternating Current (a.c.) - electric current that flows in constantly reversing directions - e.g. bread toaster, hair dryer, air conditioner (devices) Cathode Ray Oscilloscope (C.R.O.) - to show differences in the shape of graph, direction of current and voltage change for a.c. and d.c. Nuclear reaction Boiling water produces steam Steam rotates the turbine Electricity is produced Biomass produces methane Boiling water produced steam Steam rotates turbine Electricity is produced
6.2 Transformer Step-up Transformer and Step-down Transformer Transformer - device for changing the voltage of an a.c. - made of laminated soft iron core that wrapped by 2 insulation coil Step-up transformer Step-down transformer Primary voltage is lower than secondary voltage. Primary voltage is higher than secondary voltage. Turns of primary coil is less than secondary coil. Turns of the primary coil is more than secondary coil. Solving Problems Related to Transformer in Daily Life Transformer Equation Formula: = 6.3 Transmission and Distribution of Electricity Functions of the Components in the Electricity Transmission and Distribution System How is electricity transmitted and distributed? ① Generators at power stations produce a.c. (11kV or 25kV) ② - a.c. from generator is transmitted to step-up transformer. - a.c. is increased to 132kV, 275kV or 500kV ③ high voltage a.c. is transmitted to National Grid Network ④ - at the end of grid, a.c. flows to switch zone at main substation - switch zone enables electricity to be sent to branch substation - also enables power station/grid to be closed for maintenance ⑤ - at main substation & branch substation, a.c. is transmitted into a step-down transformer - the voltage of a.c. will be reduces according to their needs: ❖ heavy industrial area (33kV) ❖ light industrial area (11kV) ❖ office, business & residential area (240V) Electrical Wiring System in Malaysia One-phase wiring - suitable and stable enough for electricity usage <10kW or 50A - e.g. in rural residential areas Three-phase wiring - suitable and stable for electricity usage >10kW or 50A - e.g. in commercial and industrial areas
Electricity Supply and Wiring System in Home 3-pin Plugs and 2-pin Plugs International Colour Code for Wiring Safety Components in the Wiring System in Homes Fuse Function of Fuse - to protect the electrial appliances from any excessive current Structure of Fuse
Cartridge Fuse and Replaceable Wire Fuse Determining the Value of a Fuse - depends on the maximum current value that flows into the circuit or electrical appliances - should have slightly higher value than the maximum current - e.g. electrical kettle with current of 11.34 A should use 13 A fuse 6.4 Calculate the Cost of Electricity Consumption Energy Efficiency - percentage of energy input converted to useful form of output Energy efficiency = Useful energy input Energy input supplied × 100% Technology which Applies the Concept of Energy Efficiency Lighting devices Filament lamp compact fluorescent lamp, CFL LED lamp Structure Energy efficiency ± 10% ± 50% ± 90% Use of Electricity in Electrical Appliances Electric Meter - to measure the quantity of electricity used Electric Power, P - rate of electric energy used by an electrical device. (S.I. unit = watt) Electrical power, (W) = Electrical energy used, (J) Time taken, (s) Electric Current, I - rate of flow of electric charge through a conductor. (S.I. unit = ampere(A)–electric current, coulomb(C)–electric charge) Electric current,(A) = Electric charge, (C) Time taken, (s) Voltage, V - the electrical energy used to move a unit of electric charge through a conductor. (S.I. unit = volt) Voltage, (V) = Electrical energy used, (J) Electric charge, (C) Calculating Flow of Current through Electrical Appliances , = , × , Calculating the Cost of Electrical Energy Used Formula: (ℎ) = () × (ℎ) Ways to Save Electrical Energy Consumption Green Building Features: - efficient ventilation system to reduce the use of a/c and fans - maximising the use of natural lighting to reduce the cost of electrical energy consumption - installation of solar panels as a renewable energy source to replace conventional energy sources
Chapter 7: Energy and Power TOPIC SUBTOPIC EXPLANATION 7.1 Work, Energy and Power Work - the product of force and displacement in the direction of force. Formula: = W = Work F = Force (N) s = displacement (m) Energy and Power - the ability to do work. Formula: = P = Power W = Work done (J) t = Time taken (s) 7.2 Potential energy and Kinetic Energy Gravitational Potential Energy - the work done to lift an object to a height from the Earth’s surface. Formula: = ℎ m = mass (kg) g = gravitational acceleration (m s-2 ) h = height (m) Elastic Potential Energy - the work done to compress/stretched an elastic material over displacement of from an equilibrium position. Formula: = 1 2 F = Force (N) = displacement (m) Kinetic Energy - the energy possessed by a moving object. Formula: = 1 2 2 m = mass (kg) v = velocity (m s-1 ) 7.3 Principle of Conservation of Energy Principle of Conservation of Energy - energy cannot be created or destroyed but can only be converted from one form to another. Oscillating Systems Obey the Principle of Conservation of Energy - experienced the transformation in the form of energy. Transformation of Kinetic Energy and Potential Energy in a Closed System - total KE & PE is constant.
Chapter 8: Radioactivity TOPIC SUBTOPIC EXPLANATION 8.1 Discovery of Radioactivity History of Radioactivity ① 1895, Wilhelm Roentgen discovered x-ray. ② 1896, Henri Becquerel discovered radioactivity. ③ 1897, Marie & Pierre Currie detected radioactivity through its ionising effects. ④ Marie Currie died at the age of 67 from a disease caused by prolonged gamma ray exposure Radioactivity - a random and spontaneous decay process of an unstable nucleus by emitting radioactive radiation (, , ) Radioactive elements Product of decay Uranium-238 Thorium-234 + Helium nucleus () Thorium-234 Protactinium-234 + Electron () Cobalt-60 Cobalt-60 + gamma ray () Radioactive Decay - random and spontaneous process where an unstable nucleus emits radioactive radiation until the nucleus become more stable. - e.g. C-14, Rn-222, Th-234, U-238 Units of Radioactivity curie (Ci) becquerel (Bq) 1 Ci = 3.7 × 1010 decays/s 1 Bq = 1 decay/s Half-life of Radioactivity Decay - time taken for the number of undecayed nuclei to be reduced to half of its original number. 8.2 Atom and Nucleus Atom - According to Dalton’s Atomic Theory, an atom is the smallest particles and cannot be further divided. Structure of Atom Formation of Positive and Negative Ion Positive Ion (Cation) - an atom that loses electrons Negative Ion (Anion) - an atom that gains electrons
8.3 Ionising Radiation and Nonionising Radiation Ionising Radiation and Non-ionising Radiation Ionising Radiation - radiation that produces +ve and -ve ions while passing through air Non-ionising Radiation - radiation that doesn’t produces ions while passing through the air Types of Ionising Radiation Type of radioactive radiation Alpha radiation, Beta radiation, Gamma ray, Natural characteristic Helium nucleus Electron Electromagnetic wave Charge Positive Negative Neutral Ionising power High Moderate Low Speed 5% of light speed Almost light Same as light Penetration power Low Moderate Lead Deflection by electric field Deflection by magnetic field Sources of Ionising Radiation in the Environment Sources of ionising radiation in the environment Natural Man-made - Cosmic rays - Background radiation - Nuclear accidents - Nuclear tests - Use of radioisotope for medical purposes - Background radiation Cosmic Rays (Galactic Cosmic Rays) - high-energy radiation produced outside the Solar System Background Radiation - released from various source incl. natural and man-made - cosmic rays - radiation from natural radioactive substances fr. surroundings - radioactive wastes from nuclear accidents and nuclear tests - radioisotopes from medical use
Unit of Dose Rate Measurement for Background Radiation - microSievert/hour (Sv/h) - 1 Sv = 1 J of ionising energy absorbed by 1 kg of living tissue Safe Background Radiation Dose in Daily Life ❖ < 0.2 Sv/h ❖ < 0.0002 mSv/h ❖ < 1.752 Sv/year ❖ < 1.752 mSv/year Estimation of dose rate of ionising radiation: X-ray 5.5 mSv/medical test Smoking 55 mSv/cigarette Building 1.5 mSv/year Food 0.1-0.5 mSv/year Environment 0.4-1.0 mSv/year Flight 0.003 mSv/h High altitude 0.3-0.5 mSv/year Outer space 0.35 mSv/year TV/computer 0.01 mSv/h Risks from Exposure to Natural Ionising Radiation Source of radiation Safety measures Background radiation Use appropriate PPE (anti-UV spectacles, anti-UV umbrellas) Taking x-ray X-ray taken with doctor’s prescription Television Ensure distances from television is >2m Food contaminated with radioactive substances Don’t eat food produced in areas that contaminated with substances ( fish that came from contaminated sea) Cosmic rays Working hours of pilots are limited as they are exposed to cosmic rays 8.4 Uses of Radioactive Radiation Radioactive Radiation in Daily Life ① Archaeology and Geochronology - Carbon-12 (C-12) - to determine age of fossils ② Industry - radiation - to monitor the thickness of metal sheets ③ Agriculture - Phosphorus-32 (P-32) - to determine absorption rate of phosphate fertilisers in plants ④ Defence - nuclear bomb ⑤ Food Preservative - gamma rays, - preserve food, kill bacteria, (Radura logo) ⑥ Medical - rays from caesium-137 (Cs-137) or Cobalt-60 (Co-60) - kill cancer cells - Sodium-24 (Na-24) - to determine location of blood clots - Technitium-99 (Tc-99) - to treat tumours in the brain - Cobalt-60 (Co-60) - to destroy germs
- Iodine-131 (I-131) - to treat thyroid glands Safe and Proper Handling of Radioactive Substances and Radioactive Waste ① Store radioactive source/waste in containers with thick lead wall. ② Radioactive aubstances are shielded with thick slab of lead. ③ Using robotic hands to handle radioactive substances. ④ Detecting the dose rate of radioactive radiation absorbed into the body using detectors such as radiation badges. ⑤ Disposal of radioactive waste done safely and properly. ⑥ Wearing appropriate protective clothing when handling radioactive substances. Chapter 9: Space Weather TOPIC SUBTOPIC EXPLANATION 9.1 Activities of the Sun that Affect Earth Stucture of the Sun Phenomena that Occur on the Surface of the Sun Granules, Sunspot and Solar Cycle - photosphere are made of granules (grainy structure) - upper part of convection zone (extremely hot ± 5800°C) - sunspot are the dark regions seen on the sun - dark because temperature are lower than the surroundings - location of very large eruptions in the photosphere - can last for more than a week - always exist in pairs or groups - sun cycle is the activity of the sunspots seems to appear and disappear according to a cycle that last 11 years Prominence - huge loop of glowing gases over the sunspot - can reach heights of hundreds of thousands of kilometres - can last for several days or months - can throw out matter from the Sun, speed=600-1000km s-1 Solar Flares - column of large amounts of charged gases erupting from the Sun - strong gas explosion - attain max. brightness within a few seconds or minutes and become dim after a few minutes or hours - spout charged gas particles at high speeds into outer space - light from solar flares takes 8 min to reach the Earth - charged gas particles take 10 min to reach the Earth - collide with atoms & molecules on atmosphere & create aurora Coronal Mass Ejections - huge cloud of plasma that erupts from Sun together w/ solar flares - ejection of magnetic gas particles and appears like expanding cloud - take 3 days to reach the Earth - collide with atoms & molecules on atmosphere & create aurora Solar Wind - particles(electron,proton,) that erupt from the Sun to outer space
Earth’s Magnetosphere and its Importance Shape of Earth’s Magnetosphere Definition of Earth’s Magnetosphere - region in outer space surrounding the Earth where the Earth’s magnetic field combine with outer magnetic field Formation of Earth’s Magnetosphere - formed by interaction between the magnetic field brought by the solar wind and Earth’s magnetic field Importance of Earth’s Magnetosphere - function as a biological shield to protect the Earth from solar wind - blocks particles such as electrons, protons and alpha particles - excessive no. of particles will interrupt telecommunication etc. - reduces the pressure exerted by solar wind on Earth’s atmosphere 9.2 Space Weather Space weather and its Effect on Earth Space Weather - phenomena that occur on the surface of the Sun - solar flares, prominence, sunspot, coronal mass ejection - phenomena that occur in the space - solar wind, solar radiation storm, geomagnetic storm Interpretion of Data on Space Weather Data on space weather is used or analysed to: - forecast when coronal mass ejections occur in the Sun - determine the reasons for the occurance of solar flares and coronal mass ejections on the surface of the Sun
Chapter 10: Space Exploration TOPIC SUBTOPIC EXPLANATION 10.1 Development in Astronomy Historical Development of the Solar System Model History of the Solar System Model ① Ptolemy (90 – 168 A.D.) - Greek astronomer, astrologer and geographer - built the geocentric model, Earth at the centre & circular orbits Geocentric model - ‘Geo’ means Earth - ‘Centric’ means centre - Earth is at the centre of Solar System - Earth is stationery, other planets revolve around Earth in circular orbit ② Copernicus (1473 – 1543) - Polish astronomer, mathematician, economist and doctor - built the heliocentric model, Sun at the centre & circular orbits Heliocentric model - ‘Helio’ means the sun - ‘Centric’ means centre - Sun is at the centre of Solar System - Earth rotates on its axis and revolves around the Sun in circular orbit ③ Kepler (1571 – 1630) - German astronomer, mathematician and astrologer - modified the heliocentric model with the Sun at one common focal point on the elliptical orbits of the planets according to Kepler’s Law Modified Heliocentric model according to Kepler’s Law
10.2 Development of Technology and its Application in Space Exploration Development in Space Exploration ⑴ 11th century: Chinese invented gunpowder and used primitive rockets in battles ⑵ 1609: First telescope used in astronomy field by Galileo Galilei ⑶ 1957: First satellite – USSR Sputnik 1 ⑷ 1961: First human to orbit Earth – Yuri Gagarin (USSR Vostok 1) ⑸ 1969: First human to set foot on the moon – Neil Armstrong (US Apollo 11) ⑹ 1973: First Jupiter flyby – US Pioneer 10 ⑺ 1981: First flight of US space shuttle – Columbia ⑻ 1989: First Neptune flyby – US Voyager 2 ⑼ 1990: US launched Hubble Space Telescope from space shuttle Discovery ⑽ 1996: Malaysian satellites MEASAT 1 and 2 launched ⑾ 2000: Malaysia’s first microsatellite TiungSAT-1 launched ⑿ 2002: National Space Agency(Agensi Angkasa Negara)established ⒀ 2011: Construction of International Space Station (ISS) completed Applications of Technology in Space Exploration and their Importance Space Telescope Rocket Satellite - first satellite – Sputnik 1 was sent to outer space in 1957 - weather satellite – GOES-16 collecting data on solar flares:
Space Probe - a spacecraft that gathers information and sends it back to Earth - travel into and out of the Solar System - carry cameras and remote sensing instruments - also carry radio transmitter & receiver for communication purpose Remote Sensing - method of gathering & recording information from a distance - Malaysia, TiungSAT-1 is fitted with remote sensing instrument - to detect visible, ultraviolet and infrared light produced by object on the surface or below the surface of the Earth - data sent to 2 data receiving stations at: - National Planetarium Station, Federal Territory of Kuala Lumpur - Mission Control Station (MCGS), Bangi, Selangor Remote sensing technology is also used in various fields in daily life ① Agriculture - to detect suitable regions for agricultural development ② Geology - to detect mineral sources, mass depletion and land depletion ③ Disaster management - to identify pollution and forest fire ④ Defence - to detect intrusions of enemy ships, aircraft and vehicles