Properties of Matter–9th Standard Science Question Bank

Properties of Matter

Choose the right answer .

1. The most malleable metal is ---------------

a. Copper b. Silver c. Gold  d. Iron

2. The unit of stress is --------------------

a. Kgm-2 b. Nkg-1 c. Nm-2  d. N

Answer the following questions

1. Define matter.

Anything that occupies space & have mass is called matter.

2. Write states of matter.

Matter exists in three states. They are 1. Solid state, Liquid state & Gaseous state.

3. Mention the characteristics of solid state.

Characteristics of solid state are

1. Particles are rigidly binded.

2. They have definite shape & size.

4. Mention the characteristics of liquid state.

Characteristics of liquid state are

1. Particles are loosely binded.

2. They have in definite shape but definite size

5. Mention the characteristics of gaseous state.

Characteristics of gaseous state are

1. Particles are freely binded.

2. They have no definite shape & size

6. What is elasticity?

The property of a substance to regain its original position when the external energy is removed is called elasticity.

7. What is rigid body?

Body which do not experience any deformation on the application of external forces is called a rigid body.

8. What is elastic body?

Body which resists any deformation & recover to original state, on the removal of external forces is called an elastic body.

9. What is plastic body?

Body which do not resists any deformation & cannot recover to original state, on the removal of external forces is called a plastic body.

10. Write the unit of strain.

Unit of strain is Pascal or Nm-2

11. State Hook’s law.

For small deformations Stress and Strain are proportional to each other. This is called Hook’s law.

12. Explain Hook’s law.

For small deformations Stress and Strain are proportional to each other. This is called Hook’s law.

Stress α strain

Stress α E X strain

Here E is the proportionality constant called modulus of elasticity or elastic constant.

13. Define modulus of elasticity or elastic constant.

Modulus of elasticity or elastic constant is defined as the ratio of stress to strain.

E = Stress /Strain

Here E = modulus of elasticity or elastic constant.

14. Mention the elastic behavior of materials.

1. While designing a building knowledge of elastic properties of materials like steel, concrete is essential.

2. A bridge has to be designed such that it can withstand the load of flowing traffic, force of wind & its own weight.

3. Elastic behavior of the material is helpful in designing the shapes of pillars & columns in the buildings.

4. Hazards can be prevented, if thickness of the rope is decided previously in cranes.

15. What is malleability?

The property of hammering metals into thin sheets is called malleability.

16. What is ductility?

The property of drawing metals into wires is called ductility.

17. What are stress & strain?

The restoring force per unit area is called Stress.

The fractional change in the dimension of a body produced by the external force acting on it is known as strain.