The average thermal energy for a mono-atomic gas is : (kB is Boltzmann constant and T, absolute temperature)

\(\frac{5}{2} K_B\) T \(\frac{7}{2} K_B\) T \(\frac{1}{2} K_B\) T \(\frac{3}{2} K_B\) T

\(\frac{3}{2} K_B\) T

Degree of freedom for monoatomic gas = 3 ∴ Kinetic Energy = \(\frac{3}{2} K_B\) T