Give the molecular model for a solid and use it to explain why a solid has a definite volume and a definite shape.

Features of molecular model for a solid are :

1. There is a strong force of attraction (strong inter-molecular force) between the molecules of a solid.
2. The molecules in a solid are closely packed with negligible intermolecular space, so solids cannot be compressed much. Their orderly arrangement gives them a definite shape.
3. The molecules vibrate on either side of their mean positions but they do not leave their positions. Therefore solids have a definite size.
4. The molecules of a solid are packed tightly and so they generally have a high density.

Thus, this model concludes that solids are rigid, they have a definite size, definite shape and a definite volume.