DK014 CHAPTER 1

DK014

CHAPTER 1
MATTER

CHAPTER 1: MATTER C1 C2 C3 C4
√
1.1 DEFINITION AND CLASSIFICATION
√
Learning outcomes
(a) Define matter
(b) Classify matter into pure substances (elements and compounds)

and mixture (homogeneous and heterogeneous)

MATTER
 Definition: Matter is anything that has mass and takes up space.
 Example: air, earth, animals, trees, atoms
 The three states of matter are solid, liquid and gas
 Chemistry is the study of the properties of matter and how matter changes.

CLASSIFICATION OF MATTER

Matter

Mixtures Separation by physical method Pure Substances

Homogeneous Heterogeneous Compounds Separation Element
Mixtures Mixtures by chemical

method

 All matter can be classified based on its composition. It is either a MIXTURES or a PURE
SUBSTANCE.

MIXTURES
 Definition: A mixture is a combination of two or more kinds of matter each of which retains its

own composition and properties.

Mixture

Homogeneous Mixture Heterogeneous Mixture

Characteristics Of A Mixture :

1. Mixtures can be either heterogeneous or homogeneous.

2. The different types of matter which make up the mixture can be separated by physical changes.

3. The separated matter has basically the same characteristic properties and identities as found in
the mixture. The properties of a mixture therefore, are a combination of the properties of the
different kinds of matter it contains.

4. The composition of a mixture can contain varying amounts of different kinds of matter, within
the same sample or from one sample of the mixture to another. This shows that mixtures have
variable composition.

Homogeneous mixtures Heterogeneous mixtures
Heterogeneous or non-uniform mixtures are
 Homogeneous or uniform mixtures are ones in  those in which the composition varies
which the composition is same throughout. throughout and can be easily separated into
individual substances.
 Another name for homogeneous is a solution, For example, mixing sand with iron fillings.
which is made up of a solvent, usually taken to be
the substances present in larger amount, and one  Mixture of iron fillings and sand
or more solutes.

 Most commonly, the solvent is a liquid, whereas
solute may be solids, liquids or gases. For instance,
dissolving a spoonful of sugar in water.

Example of homogeneous mixture (a) (b)

(a) Illustration of uniform distribution of components

in homogeneous mixture
(b) Uniform distribution of components in

heterogeneous mixture

PURE SUBSTANCES

 Definition: A pure substance is a homogeneous sample of matter that always has the same
composition and properties, regardless of its source. Substances can only be homogeneous and
have constant composition. They are classified as either compounds or elements

 A compound is a homogeneous substance made up of two or more elements chemically
combined.

Characteristics of Compound :

1. Elements in a compound are combined in a definite proportion (ratio) by mass. This proportion
is the same in all samples of the compound—constant composition.

2. The chemical and physical properties of a compound are different from the individual
components which form the compound.

3. Compounds can be formed or decomposed by chemical changes. When decomposed, some
breakdown into elements, others into elements and simpler compounds. For instance, molten
sodium chloride can be broken down into metallic sodium and chlorine gas through electrolysis

Figure: Different properties of sodium metal and chlorine gas in comparison with sodium chloride
compound formed when combining sodium metal and chlorine gas together chemically.

ELEMENT

 Definition: An element is a pure substance that cannot be broken down into any other
substance by chemical or physical means.

 Elements are the simplest substances. Each element can be identified by its specific physical and
chemical properties.

 Particles of Elements - An atom is the basic particle from which all elements are made. All matter
is composed of some combination of elements

 When Atoms Combine - When atoms combine, they form a chemical bond, which is a force of
attraction between two atoms. In many cases, atoms combine to form larger particles called
molecules-groups of two or more atoms held together by chemical bonds.

 Examples of elements: gold, oxygen, copper

(a) (b)
Figure: (a) Illustration of composition of gold atoms in gold coin.

(b) Illustration of oxygen molecules.

EXAMPLES:

Classify each of the materials below. In the center column, state whether the material is a pure
substance or a mixture. If the material is a pure substance, further classify it as either an element or
compound in the right column. Similarly, if the material is a mixture, further classify it as
homogeneous or heterogeneous in the right column.

Material Pure Substance Element, Compound,
or Mixture Homogeneous, Heterogeneous
concrete Mixture
sugar + pure water Heterogeneous
(C12H22O11 + H2O) Mixture
Homogeneous
iron filings (Fe) Pure Substance
Pure Substance Element
limestone (CaCO3) Compound
Mixture Heterogeneous
orange juice (w/pulp) Mixture Heterogeneous
Mixture Homogeneous
Pacific Ocean Pure Substance
Pure Substance Element
air inside a balloon Pure Substance Element
Mixture Compound
aluminum (Al) Mixture Homogeneous
Pure Substance Heterogeneous
magnesium (Mg) Pure Substance Compound,
Mixture Element,
acetylene (C2H2) Heterogeneous
Mixture
tap water in a glass Homogeneous
Pure Substance
soil Mixture Compound
Heterogeneous
pure water (H2O) Mixture
Homogeneous
chromium (Cr) Pure Substance
Compound
Chex mix
salt + pure water

(NaCl + H2O)
benzene (C6H6)

Muddy water
brass

(Cu mixed with Zn)
baking soda (NaHCO3)

EXERCISES :

1. Classify each of the following as either substance or mixture. If it is a substance, write element
or compound in the appropriate column. If it is a mixture, write heterogeneous or
homogeneous in the appropriate column.

Type of matter Substance Mixture
Chlorine (Cl2)
Water (H2O)
Lucky Charms
Salt water
Nitrogen (N2)
Salt (NaCl)
Rocky road ice cream
Rubbing Alcohol
Pure air
Iron (Fe)
bronze
Spaghetti and meatballs

2. Compare and contrast a mixture and a compound. How are they alike? How are they different?

3. State a difference between a compound and a solution.

4. Label each substance listed below as an element (E), compound (C), heterogeneous mixture
(He), or homogeneous mixture (Ho)

a. _______ Barium (Ba)
b. _______ Carbon Monoxide (CO)
c. _______ Soil
d. _______ Kool-Aid
e. _______ Brass (CuZn)
f. ________ Air
g. _______ Vegetable soup
h. _______ Carbon (C)
i. _______ Baking Soda (NaHCO3)
j. _______ Jello with fruit
k. _______ Gold (Ag)
l. _______ Milk
m. _______ Sand
n. _______ Orange juice without pulp
o. _______ Orange juice with pulp

1.2 STATES OF MATTER C1 C2 C3 C4
√√
Learning outcomes

(a) Explain the general properties of solid, liquid and gas in terms of
arrangement of particles, shape, density and compressibility.

MATTER

 In facts, all matter that exist naturally on earth can be classified as one of these physical forms,
which are called states of matter.

 Matter can exist in three physical forms/states: solid, liquid and gas.
 So, each of the three common states of matter can be distinguished by the way it fills it

container.

Matter exists in 3 Physical State

Solid Liquid Gas

SOLID
 A solid is a form of matter that has its own definite/fixed shape and volume.
 Because its shape is definite, a solid might not conform to the shape of the container in which it is placed.
If you place a rock in a container, the rock will not take the shape of the containers.
 Examples: Wood, iron, paper and sugar
 The particles of matter in a solid are tightly packed or are held closely together in orderly manner and
at fixed positions with little freedom of motion (particles vibrate about fixed positions)

 The tight packing of particles in solid makes it incompressible, that is it cannot be pressed into a smaller
volume.

 Incompressible materials will maintain their density. So solid particles have a high density.

LIQUID
 A liquid is a form of matter that has a constant/definite volume and takes the shape of
container. Common examples of liquids include water, blood and mercury.
 Particles in a liquid are close together but are not held so rigidly in position and can move past
one another or slide past one another freely. This property allows liquid to flow and take the
shape of containers.

 Because of the way the particles of a liquid are packed, liquid is virtually incompressible or can
be compressed slightly.

 Liquid has a high density because the particles in liquid are free and can move around, but the
density of liquid less dense than solid.

GAS
 A gas is a form of matter that not only flows to conform to the shape of its container but also
fills the entire volume of its container. Thus, gas does not have fixed shape and volume.
 In a gas, the particles are far apart and move in random motion. Because of the significant
amount of space between particles of gases are easily compressed.

 Gases have lower density than other states of matter, such as solids and liquids.

COMPARISON BETWEEN SOLID, LIQUID AND GAS

PROPERTIES OF MATTER SOLID LIQUID GAS

Arrangement of particles Closely packed in Closely packed in an Far apart in random
arrangement
an orderly disorderly

arrangement arrangement

Shape Fixed Not Fixed Not Fixed
Density Very Dense Least Dense
Compressibility Dense Compressible
Not Compressible
Not
Compressible

EXERCISES :
1. a) Each particles of argon can be represented by a circle. Draw the particles to show solid

argon, liquid argon and argon gas in the box below.

Solid Liquid Gas

b) i. If the particles a move around quickly in any direction within the container, the argon

is __________________

ii. If the particles are very close together in definite pattern and can only vibrate in

position, the argon is ________________

iii. If the particles are close together but not always touching and can move in any

direction, the argon is __________________

2. There are three states of matter : solid, liquid and gas.
a) Give one property that liquids and gases have in common.

b) Give one property in which liquids and gases differ.

3. Complete the table below

Solid Liquid Gas

Does it have its own
shape?

Does it have a
definite volume?

How are the
particles arranged?
How are the density

of particles ?
Does it can be
compressed?

1.3 ELEMENTS C1 C2 C3 C4
√
Learning outcomes
(a) Define element √
(b) Introduce the period and group of elements in the periodic table

(Limited to group 1, 2 and 13 to 18).

ELEMENT
 Definition: A substance that cannot be decomposed into simpler substance
 Each element has identical atoms (except for isotopes, different numbers of neutrons) which are physically
and chemically identical and each element has its own unique physical and chemical properties, but there
are important patterns in properties when looking at a particular column (group) or row (period or series)
of the periodic table.
 Each element has its own unique chemical symbol which is used to denote elements in the periodic table,
in chemical formulae and chemical equations e.g. hydrogen is H, copper Cu, chlorine Cl or potassium K.
The symbol is a single capital letter (upper case e.g. C, N, O, F, C, P etc.) or a capital letter followed by a
lower case letter (e.g. Cu, Fe, Cl, Br, Li etc.).

PERIODIC TABLE
 Definition: An arrangement of the elements in order of increasing proton number. Elements with
similar physical and chemical properties are listed in vertical column
 The elements are grouped in the same period because have same number of shells filled with
electrons.
 The vertical columns in the Periodic Table are called groups.
 The elements with same number of valence electrons in the outermost shell are gathered in the
same group. Same number of valence electrons in the outermost shell causes the elements in
the same group to have similar chemical properties.
 The elements are divided into metals, nonmetals, and metalloids.
 Most elements are metals on the left and lower parts of the periodic table. Metals are good
conductors of heat and electricity.
 Non-metals are on the right and towards the top of the periodic table.

 The thick diagonal zig–zag black line shows the main division between metals on the left of the
periodic table and non–metals on the right of the periodic table. Nonmetals are poor conductors
of heat and electricity.

 However, note that the metallic elements and non–metallic elements adjacent to this zig–zag line
can show a metallloids properties.

 Metalloids have properties that are intermediate between those of metals and nonmetals. The
elements change from metallic to nonmetallic as you go across the table left to right

PERIODIC TABLE OF ELEMENTS

PERIODIC TABLE

PERIOD GROUP

Terms Description
PERIOD  A horizontal row of the periodic table
 Elements in the same period have the same number of energy levels. The row
GROUP
number is the number of energy levels.
 Periodic table contains 7 periods with each one beginning at the far left. New

period begins when a new principal energy level begins filling with electrons. So
first period contains two elements H and He
 In second period, electrons start to fill from Li and it gets 8 electrons up to Ne
(atomic number 10). So second period contains 8 elements Li, Be, B, C, N, O, F and
Ne.
 In third period, electrons start to fill from Na and get 8 electrons up to Ar (atomic
number 18) and contain 8 elements Na, Mg, Al, Si, P, S, CI and Ar.
 Similarly, 4th, 5th, 6th and 7th periods are completed with different number of
electrons. In this way number of elements in different periods is as follows.
 Periods 4 and 5 have 18 elements. Periods 6 and 7 have 32 elements because the
two bottom rows that are separated from the rest of the table belong to those
periods.
 A vertical column of elements in the periodic table
 Periodic Table contain 18 groups.
 Group 1 contains seven elements Hydrogen, Lithium, Sodium, Potassium,
Rubidium, Caesium and Francium (H, Li, Na, K, Rb, Cs and Fr). These elements are
called as alkali metals and this group is also called as alkali metal group, because
the elements easily form strong bases on reaction with water.
 Group 2 contains 6 elements Beryllium, Magnesium, Calcium, Strontium, Barium
and Radium (Be, Mg, Ca, Sr, Ba and Ra). These elements are called as “Alkaline-
earth metals” and this group is called “Alkaline-earth metal group”, because their
oxides are alkaline in nature and present in earth.

 Group 13 to 17, all the groups contain 5 elements each.
 Group 16 contains 5 element.It consists of the elements oxygen, sulfur, selenium,

tellurium and polonium. These elements also called as chalcogens and can be
found in nature in both free and combined states.
 Group 17 contains 5 elements Fluorine, Chlorine, Bromine, Iodine, Astatine or F,
CI, Br, I and At. These elements are called as halogens and this group is called as
‘halogen group’ because the elements react with metals to form salts
 Group 18 contains 6 elements, Helium, Neon, Argon, Krypton, Xenon and Radan or
He, Ne, Ar, Kr, Xe and Rn. The elements are gases and do not react with any other
element in normal conditions, so they are called as Inert gases or noble gases.

1. EXERCISE

A D
B E
C

The figure above shows the elements A, B, C, D and E.
a) How are the elements A to E arranged in the periodic table?
b) Which elements are in the same group.

c) Which elements are in the same period?

d) Which of the elements are in group 1 and 18?

2. Directions: Answer the questions with the proper information using your notes, book, and the periodic
table.

1. What is a group? _______________________________________________________

2. What is a period? ________________________________________________________

3. What is the symbol for the following elements?

a. Magnesium _____________ b. Potassium ______________

c. Iron _______________ d. Neon ____________

4. What are the names of the following elements?

a. C __________________ b. Cl _________________

c. Si _________________ d. Sr _________________

5. What period are the following elements in?

a. He _______________ b. Ge _________________

c. Rb _______________ d. I __________________

6. What group are the following elements?

a. Sulfur _______________ b. Ca _________________

c. Iodine _______________ d. Ga _________________

7. Give me an atom with the following characteristics.
a. Halogen _________________b. Chalogen ________________
c. Alkali metal _____________ d. Nobel gas________________
e. Alkaline Earth metal ________________

8. Elements in group 2 are called as ____________________
9. What element is in group 4 period 5? _________________
10. How many elements are in period 9?__________________
11. What is the last element in period 4?__________________

1.4 PHYSICAL AND CHEMICAL CHANGES C1 C2 C3 C4
√
Learning outcomes
(a) Describe the physical and chemical changes of matter.

INTRODUCTION
Chemistry is the study of matter and the changes it undergoes. These changes can be broken down
into two classes, physical changes and chemical changes

PHYSICAL CHANGE

 Physical changes occur when the appearance of a substance changes, but chemically the
substance is the same. The individual molecules do not change. Means, no new substance is
formed because the chemical identity doesn’t change.

 Example: When ice melts, the molecules of water become farther apart but the molecules are
still water – 2 hydrogen atoms and 1 oxygen atom (H2O).

 In a physical change, one or more of the physical properties is changed.
 Examples of such physical properties include size, shape, and physical phase or state.
 Examples of physical changes are melting, freezing, or changing size or shape. A physical

change also occurs when substances are mixed and something dissolves like when making salt
water or Kool-Aid. The water, salt and sugar still keep their original properties and the
substances can be separated again.
 So, the ability to restore something to its original substance is a characteristic of physical
change. Some processes that produce a physical change are cutting, grinding, boiling, freezing,
melting, condensing, breaking, separating, chopping, splitting, mixing, tearing, crushing and
blending.

CHEMICAL CHANGE

 Chemical change results in the formation of one or more new substances. In a chemical
change, matter is transformed completely into different materials and new substances are
formed. These new substances will differ in chemical properties and composition from the
original substances.

 Chemical changes usually occur when two or more substances come in contact with each
other, or when heat is applied.

Sign of Chemical Change

 The outcomes, or products, of a chemical reaction cannot easily be turned back into the
original substances. Once paper is burned, it cannot be restored to its original state.

 Indications of a chemical change are change in color, production of gas (bubbles), production
of a solid (precipitate), creation of heat (exothermic reaction), or cooling (endothermic
reaction), light being given off and production of an odor

Common Examples :
Combustion  Chemical change in which a substance combines rapidly with oxygen.

 Examples: paper burning, gasoline burning, hydrogen burning, gun powder

exploding

Corrosion  Chemical change in which a metal is gradually changed into a new substance.

 Examples: iron rusting, silver tarnishing, copper corroding

Cooking Food  Involves many chemical reactions

 Examples: baking a cake, cooking an egg

Life Processes  Involves the many chemical changes that occur in living organisms.

 Examples: digestion, respiration, photosynthesis

Complete the table below:

Change New Evidences Type changes:
Bending clip Substances Shape Physical(P) or Chemical ( C )

None

Tearing paper None Shape

Burning paper Yes Color change, heat, light,
Stretching rubber band (gas formed)

No Size and shape

Magnetizing nail No None

Heating nail No None

Sand + pebbles No None

Separating sand + No None
Pebbles Yes Heat, gas, color change

Mg + vinegar

Burning charcoal Yes Heat, light, color change

Heating marshmallow Yes Color change

Selzer + water Yes Gas

Crushing sugar cube No Size

Na2Co3 & Ca(OH)2 Yes Precipitate (white)

Ammonium chloride & No State, heat absorbed
water Yes Color change
No Heat, state
Windex &
phenolphthalein

Calcium chloride & water

Salt & water No State

Vinegar & limestone Yes Gas

Carbonated drink Yes Gas

EXERCISES :
1. Classify the following as being a physical (P) or chemical (C) change.

Change Type changes:

Physical(P) or Chemical ( C )

a) Sodium hydroxide dissolves in water.

b) Hydrochloric acid reacts with potassium
hydroxide to produce a salt, water, and heat.

c) A pellet of sodium is sliced in two.

d) Water is heated and changed to steam

e) Potassium chlorate decomposes to potassium
chloride and oxygen gas

f) Iron rusts.

g) When place in water, a sodium pellet catches
on fire as hydrogen gas is liberated.

h) Evaporation of alcohol.

i) Ice melting.

j) Milk sours.

k) Sugar dissolves in water.

l) Wood rots.

m) Pancakes cooking on a griddle.

n) Grass growing in a lawn.

o) A tire is inflated with air.

p) Food is digested in the stomach.

q) Water is absorbed by a paper towel.

r) Grinding coffee beans.

s) Drying clothes.

t) Baking chocolate chip cookies.

2. Identify the following as being true or false to the left of the sentence.

Sentence True or False
a) A change in size or shape is a physical change.
b) A chemical change means a new substance with new

properties was formed.
c) An example of a chemical change is when water freezes.
d) When platinum is heated, then cooled to its original state, we

say this is a physical change.
e) When milk turns sour, this is a physical change because a

change in odor does not indicate a chemical change.
f) When citric acid and baking soda mix, carbon dioxide is

produced and the temperature decreases. This must be a
chemical change.

3. Why is heating water to form water vapor not considered to be a chemical change?
4. What happens to matter in a physical change?
5. What are some examples of physical changes?
6. What happens to the particles of matter during a chemical change?
7. Give four examples of chemical changes.

8. How is a physical change different from a chemical change?

Objective Questions
1. Which of the following is an example of physical change?
a. Mixing baking soda and vinegar together, and this causes bubbles and foam.
b. A glass cup falls from the counter and shatters on the ground.
c. Lighting a piece of paper on fire and the paper burns up and leaves ashes.
d. Baking a birthday cake for your mother.

2. Which of the following is an example of chemical change?
a. Filling up a balloon with hot air.
b. Taking a glass of water and freezing it by placing it in the freezer.
c. A plant collecting sunlight and turning it into food.
d. Your dog ripping up your homework.

3. Which change can be easily reversed, for the most part?
a. Chemical Change
b. Physical Change
c. Both a physical and chemical change
d. Neither a physical or chemical change

4. When a new substance is formed with different properties than the original substance it is
called a
a. Chemical change
b. Physical change
c. Freezing
d. Boiling

5. If the chemical properties of a substance remain unchanged and the appearance or shape of an
substance changes it is called a
a. Chemical change
b. Physical change
c. Both a physical and chemical change
d. Neither a physical or chemical change

6. Which is an example of a physical change?
a. Metal rusting
b. Silver tarnishing
c. Water boiling
d. Paper burning

7. What characteristic best describes what happens during a physical change?
a. Composition changes
b. Composition stays the same
c. Form stays the same
d. Mass is lost

8. Which is an example of chemical change?
a. Water freezes
b. Wood is cut
c. Bread is baked
d. Wire is bent

9. Which is not a clue that could indicate a chemical change?
a. Change in color
b. Change in shape
c. Change in energy
d. Change in odor

10. What property stays the same during physical and chemical changes?
a. Density
b. Shape
c. Mass
d. Arrangement of particle

11. Which of the following is a physical change?
a. Iron is oxidized to iron oxide
b. Aluminum is pounded into thin sheets
c. Copper reacts with a strong acid
d. Sodium metal explodes on contact with water

12. Which of the following is an example of a chemical change?
a. Melting gold
b. Burning hydrogen
c. Dissolving sugar in water
d. Breaking a sheet of glass

13. Which of the following is a common sign that a chemical change has occurred?
a. A chemical has changed size
b. A chemical has changed states
c. A chemical has become a different shape
d. A chemical has turned a different color