According to Dulong `&` Petits law, molar heat capacity of solids at room temperature is nearly equal to 3R. This can be explained using law of equipartition. Each atom of solid is boned to neighboring atoms by interatomic forces. Each atom can vibrate about its equilibrium positum. So each atom has 6 degrees of freedom. But in relaity, the molar heat capacity of solids varies. with temperature as shown in figure.

At low temperature, the heat capcities decrease with decreasing temperature. This is due to the fact that variational degrees of freedom are frozen out at low temperatures.
Selec the correct statement(s).

Options

A. A sample of lead requires less heat to go from 100K to 150K then to go from 300K to 350K
B. A sample of lead requires more heat to go from 400K to 440K then to go from 100K to 140K
C. For diamond at room temperatures also vibrational degrees of freedom are partially frozen.
D. The specific heat capacity of all solids at high temperature is nearly the same.

Explanation

compare from Graph.