Physics - Heat & Thermo Question with Solution | TestHub

At N.T.P. equal volumes contain equal numbers of molecules (Avogadro's law). Both are diatomic, so $U=\frac{5}{2}nRT$ is the same for each gas. rms speed differs since $v_{rms}\propto 1/\sqrt{M}$. The average velocity (vector mean) is zero for both gases, hence the same.