Solutions of practice questions based on chapter 1 (matter ) for class 6

 1. A molecule is very small in size.The Range molecules is between 10-⁹ m to 10-¹⁰m.

2. There are three states of matteri.e., solid,liquid & gases.Ammonia belongs to gaseous state.

3. The molecules of liquid and gas move in zigzag direction continuously within the boundary surface of the container or vessel in which they are kept, in all possible directions at all possible speed .They are in astate of incessant random motion.

4. Thermal expansion takes place in all three States of matter. Thermal expansion is least in solid and most in gaseous state whereas in liquid it  is in between solid and gaseous state.

5. Maharishi Kannad was an Indian philosopher. He was the first to suggest that all forms of matter are composed of extremely small particles known as Anu and that each Anu may be made up of still smaller particles called Parmanu.

6. A molecule or a cluster of several molecules is called a nanoparticle. It is equal to 10-⁹ m.

7. A rigid body is a body whose shape and size remains same irrespective of the the force applied on to it. Example a metal ball is a rigid body for small magnitude of force. But if force is increased and shape of a metal ball is changed then it cannot be said to be a rigid body.

8. The change in state of matter of a substance from a solid to liquid or from liquid to gas is brought about by imparting heat energy to it at a constant temperature. The constant temperature at which a solid substance melt into liquid state by absorbing heat energy is called as melting point.

The constant temperature at which a liquid changes into gaseous state by absorbing heat energy from the surrounding is called as boiling point of that substance.

9. Sublimation is a process in which a solid substance directly changes into  gaseous state by absorbing heat energy from surrounding.eg. camphor,napthlene ball,ammonium chloride etc., .

Condensation is a process in which a gaseous substance Changes into liquid state by releasing heat energy to the surrounding.eg during rainfall water vapours of cloud gets converted rain water.

10. The force of attraction between the particles of two different substances is called the force of adhesion or adhesive force. While pasting a substance by using Fevicol , there are two different substances. So,There will be a force of adhesion between them.