An ideal gas and a solid of the same substance are at the same temperature. The average kinetic energy of the gas molecules is ${E_{\text{g}}}$ and the average kinetic energy of the solid molecules is ${E_{\text{s}}}$. What is the comparison between ${E_{\text{g}}}$ and ${E_{\text{g}}}$?

A.     ${E_{\text{g}}}$ is less than ${E_{\text{s}}}$.

B.     ${E_{\text{g}}}$ equals ${E_{\text{s}}}$.

C.     ${E_{\text{g}}}$ is greater than ${E_{\text{s}}}$.

D.     The relationship between ${E_{\text{g}}}$ and ${E_{\text{s}}}$ cannot be determined.

B