Kinetic energy of one molecule of an ideal gas is

The K.E equation of a gas for n moles is

$\mathrm{K}.\mathrm{E} = \frac{3}{2}\mathrm{nRT}$

The kinetic energy (K.E) for one mole of gas (𝑛 = 1 ) we can write as

$\mathrm{K}.\mathrm{E} = \frac{3}{2}\mathrm{RT}$

Note: 1 mole of any gas contains N molecules

So, K.E per one molecule is

$\mathrm{K}.\mathrm{E}=\frac{3}{2}\frac{\mathrm{RT}}{\mathrm{M}}$

$\mathrm{K}.\mathrm{E}=\frac{3}{2}\mathrm{KT} ; (\mathrm{Since} \frac{\mathrm{R}}{\mathrm{N}}=\mathrm{K})$

Therefore, the correct answer is option “B”.