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

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

The internal energy of a perfect monoatomic gas is

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

Which type of propcsty internal energy is ?

Which type of property internal energy is?

Which type of property internal energy is?

What type of motion is associated with the molecules of a gas ?

In which expansion the internal energy of a gas be decreases?