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,…

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