# Along with electrons, do molecules also directly take in photon energy from a source?

Let's take a black object for example. When waves of light (whether from the sun or a lamp) come into contact with the object, is it just the electrons (not the molecules) of the object that directly take in/contain the energy from the light source when the light waves comes in contact? Or, do the molecules also directly take in energy from the photons when the waves come into contact with the molecules?

Or, is it that the molecules just get their energy from the electrons that transfer the energy to them?

And when the object releases energy as heat, is it energy from the electrons, molecules, or both molecules and electrons that's being released?

• If the molecule has a dipole moment you can imagine that the electric field of the light can couple to this dipole moment and that it oscillates with the frequency of the light. When the frequency corresponds to one of the vibrational or rotational energies of the molecule it will excite this motion. The opposite is also true, if you look at the ammonia maser for instance, where NH$_3$ molecules are prepared in an excited level (of the inversion state, so associated with motin of the atoms) these molecules release their energy by emitting a ~24GHz photon. – Paul Aug 18 '15 at 7:18