Question

On the basis of the kinetic theory of matter , explain why
A) ---solid have a fixed shape and a fixed volume.
B) ---liquid have a fixed volume but not a fixed shape.
C) ---gases have neither a fixed shape not a fixed volume.

Answer 1

Dear Student

A) Solid has a definite shape and a definite volume. This is because the molecules in a solid are in fixed positions and are placed close together. The molecules can still vibrate but they cannot move from one part of the solid to another part. As a result, a solid does not easily change its shape or its volume.

B) Liquids have a definite volume, no definite shape & less rigidity. This is because
i) intermolecular space between particles of matter is slightly more than the solids
ii) force of attraction between the particles is less than solids,
iii) particles are free to move around in the liquid.

C) ​​​​​​Gases do not have a fixed volume and shape.This is because
i) the intermolecular forces between the gases are very weak. So, the molecules of the gases are moving randomly and freely in all the directions.
ii) the container in which gases are kept can fill the whole volume of the container irrespective of the shape of the container because the molecules randomly dispersed in all the directions.

Regards