" The internal energy of a perfect monoatomic gas is "

Consider the following statement. The internal energy of an ideal monoatomic gas may have contributions from:

Answer the question briefly and the point: Which type of motion of the molecules is responsible for the internal energy of a monoatomic gas?

On free expansion, the internal energy of the perfect gas

The internal energy of a perfect gas does not change during

The internal energy of triatomic gas is due to

Which type of motion of the molecules is responsible for internal energy of a monoatomic gas?