Using the hydrogen model, when the electron drops to the 'lowest' quantum level it emits photons in the dark blue; when it drops to the second lowest level it emits in the blue-green. When it is 'bumped up' to the second level it absorbs photons (assuming more than one atom) and when it is 'bumped up' to the third level it absorbs photons. What are the frequencies of absorbtion? Have they been identified or are they assumed by reason of emissions when the electrons drop to lower quantum levels? And what are all of these exact frequencies?