Thermal expansion of a solid is due to the

(A) : Thermal expansion of solids is due to the anharmonicity of the lattice vibrations. ( R) : As the temperature of the solid increases, the amplitude of vibrating atoms increases.

Thermal expansions of gases.

Usually the thermal expansion of a liquid is greater than the thermal expansion of an equal volume of a solid'. State whether the statement is true or false.

The coefficients of thermal expansion of a solid are found to be the same when measured in different directions. Is this an amorphous or crystalline?