Class 7 :: Chemistry :: Matter and Its Composition (ICSE Understanding Chemistry)
Matter and Its Composition
(ICSE Understanding Chemistry)
EXERCISES
A. Multiple choice questions.
1. Solids have
a. definite shape and volume. [✓]
b. definite shape only. [ ]
c. definite volume only. [ ]
d. no definite shape or volume. [ ]
2. The intermolecular force of attraction is the strongest in
a. solids. [✓]
b. liquids. [ ]
c. gases. [ ]
d. none of the above. [ ]
3. The intermolecular spaces are maximum in
a. solids. [ ]
b. liquids. [ ]
c. gases. [✓]
d. none of the above. [ ]
4. A water molecule consists of ________ hydrogen atoms.
a. 1. [ ]
b. 2. [✓]
c. 3. [ ]
d. 4. [ ]
B. True or False.
1. Only living things are made up of matter. [F]
2. Air does not have mass. [F]
3. Stone occupies space. [T]
4. A molecule is always made up of one type of atoms. [F]
5. An atom is a smallest unit of matter that can exist independently. [F]
C. Fill in the blanks.
1. Matter has mass and occupies space.
2. The space between the molecule of matter is known as intermolecular space.
3. The intermolecular force of attraction is the weakest in gaseous state of matter.
4. Liquid takes the shape of the container in which it is poured.
D. Match the following.
=
Column A | Column B |
|---|---|
1. Smallest unit of matter. | a. Solid. [2] |
2. Definite volume and shape. | b. Atom. [1] |
3. Definite volume but no shape. | c. Gas. [4] |
4. No definite volume or shape. | d. Liquid. [3] |
E. Name the following.
1. Made up of one type of atoms or different types of atoms.
= Molecules.
2. Matter that can be compressed to a great extent.
= Gas.
3. Molecules are tightly packed in this state of matter.
= Solid.
4. These are negligible in solids and large in gases.
= Intermolecular Space.
F. Diagram based questions.
1. Name the states of matter in figures (a) and (b).
= (a) - Liquid; (b) - Solid;
2. Give the type of intermolecular spaces present in (a) and (b).
= (a) - More than solids; (b) - Negligible;
3. Which one of the following has weak intermolecular forces?
= (a) i.e. Liquid has weak intermolecular forces.
G. Differentiate between the following.
1. Solid, liquid and gases.
=
Property | Solid | Liquid | Gas |
|---|---|---|---|
Intermolecular forces of attraction | Very strong. | Weaker than solids. | Very weak. |
Intermolecular spaces | Negligible. | More than solids. | Very large. |
Shape and size | Has a fixed shape and size. | No fixed shape and size. Takes the shape of the container. | No fixed shape or size. |
Volume | Has a definite volume. | Has a definite volume. | No definite volume. |
Flowing ability | Cannot flow. | Can flow from higher to lower level. | Can flow in all direction. |
Compressibility | Cannot be compressed. | Can be compressed to small extent. | Can be easily compressed. |
Example | Ice, Sugar Cube. | Water, Milk, Oil. | Air, Steam, Wind. |
2. Intermolecular force and intermolecular space.
=
Intermolecular Force | Intermolecular Space |
|---|---|
1. It is the force of attraction present between the molecules of matter. | 1. These are the spaces present between the molecules of matter. |
2. When intermolecular force is strong. | 2. Intermolecular space is negligible. |
3. When intermolecular force is weak. | 3. Intermolecular space is more. |
H. Very short answer questions.
1. Define the term matter.
= Matter is anything that has mass and occupies space.
2. In how many states can matter exist? Name them.
= Matter can exist in three states. They are - solid, liquid and gas.
3. What is matter composed of?
= Matter is composed of extremely small particles called atoms. An atom is a smallest unit of matter that shows the properties of that matter, but it may or may not be capable of independent existence.
4. Name two things on which the arrangements of atoms or molecules in a matter depend.
= The two things on which the arrangements of atoms or molecules in a matter depend are - intermolecular force and intermolecular space between the molecules.
5. Which state of matter has weak intermolecular forces?
= Gas has weak intermolecular forces.
6. Give two important features of matter in solid state.
= Two important features of matter in solid state are -
i) Solids have a fixed shape due to strong intermolecular forces of attraction between the molecules.
ii) Solids can not be compressed as their molecules are closely packed and have negligible intermolecular spaces.
7. Name the state of matter which has fixed volume but no shape.
= Liquid.
I. Short answer questions.
1. Why is air considered to be matter?
= Air is considered to be matter because air has mass and occupies space.
2. On what basis are the three states of matter defined?
= On the basis of intermolecular force and intermolecular spaces between the molecules, the three states of matter are defined.
3. What is intermolecular force of attraction in matter?
= Intermolecular force is the force of attraction present between the molecules of matter.
4. Why is intermolecular space negligible when intermolecular force of attraction is the strongest?
= Intermolecular space is negligible when intermolecular force of attraction is the strongest because the intermolecular force attracts the molecules and keep them very close.