The possible energies of photons is continuous and therefore a photon could have an infinite number of possible numerical values for energy. In contrast all forms of molecular energy are quantized (electronic, rotational, vibrational and translational). Surely the probability of any given photon having EXACTLY the right energy to be absorbed by a molecule should be negligibly small (effectively zero) since there is a finite number of possible molecular energies and an infinite number of possible photon energies. Any finite number divided by infinity is zero. I know my reasoning must be incorrect in some way but as yet no one has given me a good explanation of why so I though I would ask here.