Give reasons for the following:
$(a)$ Solids are incompressible.
$(b)$ Solids have negligible kinetic energy.

(N/A) In solids,the constituent particles are very closely packed with negligible intermolecular space. Due to this high density and lack of space between particles,they cannot be compressed further,making them incompressible.
$(b)$ In solids,the intermolecular forces of attraction are very strong,which holds the particles in fixed positions. Since the particles can only vibrate about their mean positions and cannot move freely,their kinetic energy is negligible at room temperature.