What is the internal energy of one mole of an ideal gas?

What type of kinetic energy do $He$ and $Ne$ possess?

If a gas expands at a constant temperature,then...

The energy of an ideal gas depends only on its

Assertion $(A)$ At $300 \ K$, kinetic energy of $16 \ g$ of methane is equal to the kinetic energy of $32 \ g$ of oxygen.
Reason $(R)$ At constant temperature, kinetic energy of one mole of all gases is equal.

The diffusion coefficient of an ideal gas is proportional to its mean free path and mean speed. The absolute temperature of an ideal gas is increased $4$ times and its pressure is increased $2$ times. As a result,the diffusion coefficient of this gas increases $x$ times. The value of $x$ is