f.4 Phy (Heat)2

In fact, the internal energy of an object depends on two factors.

1. Molecular kinetic energy

2. Intermolecular potential energy

K.E. depends on the temperature of the molecules only.

For intermolecular P.E., it depends on the total number of particles. You may consider more molecules contribute to more to P.E.

That's why the total also depends on the total number of molecules.