A diatomic gas molecule consists of two atoms of mass m separated by a fixed distance d

Question:

A diatomic gas molecule consists of two atoms of mass m separated by a fixed distance d rotating about an axis as indicated in Fig. 39-32. Assuming that its angular momentum is quantized as in the Bohr model for the hydrogen atom, find
(a) The possible angular velocities
(b) The possible quantized rotational energies.