The translational kinetic energy of the molecules of a gas at absolute temperature $T$ can be doubled by

The kinetic energy of one gram molecule of a gas at normal temperature and pressure is $(R = 8.31\,J/mol\cdot K)$.

$A$ flask contains argon and chlorine in the ratio of $2:1$ by mass. The temperature of the mixture is $27^{\circ} C$. The ratio of average kinetic energies of two gases per molecule is (in $:1$)

Number of molecules in a volume of $4\, cm^{3}$ of a perfect monoatomic gas at some temperature $T$ and at a pressure of $2\, cm$ of mercury is close to $?$
(Given,mean kinetic energy of a molecule (at $T$) is $4 \times 10^{-14}\, erg$,$g=980\, cm/s^{2}$,density of mercury $=13.6\, g/cm^{3}$)

The average translational kinetic energy of ${O_2}$ (molar mass $32$) molecules at a particular temperature is $0.048 \; eV$. The translational kinetic energy of ${N_2}$ (molar mass $28$) molecules in $eV$ at the same temperature is:

Estimate the average thermal energy of a helium atom at:
$(i)$ room temperature $(27^{\circ} C)$,
$(ii)$ the temperature on the surface of the Sun $(6000\; K)$,
$(iii)$ the temperature of $10$ million kelvin (the typical core temperature in the case of a star).