Question

Chapter 9!
Long Answer Questions (Pg-104)
1. Differentiate between solids, liquids and gases on the basis of the arrangement of the
particles.
Ans. In a solid, the molecules are tightly packed and in a specific pattern, thereby giving solids a
definite shape. Solids do not change in size and the molecules in solids do not move from one place
to another.
In a liquid, the molecules are loosely packed. Molecules can move easily and therefore, liquids flow
freely. Liquid takes the shape of the container in which they are kept.
In gases, the molecules vibrate and move freely at high speed. The molecules in gases are well
separated with no arrangement.
Gas
Liquid
Solid​

Answer 1

Answer:

In solids-

Here the molecules are very tightly packed and there is no or very less intermolecular space and there is high intermolecular force of cohesion.

The molecules do not move about their mean position and thus solids have a definite shape and volume

In Liquids-

Here the molecules are less tightly packed as compared to solids and also there is less force of intermolecular attraction. The intermolecular distance is greater than that in the solids. Thus, they don't have a definite shape but acquire the shape of the vessel in which they are contained but have a definite volume at a given temperature.

In gases-

Here the molecules are far apart from each other i.e. have the greatest intermolecular distance which result into the weakest intermolecular forces of attraction. The molecules as are not bound by and strong force move about freely and thus gases do not have a definite shape and also do not have any definite volume.