Which of the following gases will have the- highest kinetic energy per mole at the same pressure & temperature ?

ANS:D - All the gases will have the same KE

The kinetic energy of a gas is directly proportional to its temperature, regardless of the gas's molecular identity. Therefore, at the same pressure and temperature, all gases, regardless of their molecular identity, will have the same kinetic energy per mole. This is because the kinetic theory of gases states that the average kinetic energy of gas molecules is proportional to the absolute temperature of the gas and does not depend on the type of gas molecules present. So, the correct option is: "All the gases will have the same kinetic energy."