Quanto Mechanics - A Quantum Field Theory

In an atom, ththe electrons can have only a fix set of possible energy levels. So when if you heat up an atom by literally putting it in,. you know, having it be bouncing around e with er, e, hitting other molecules, hitting other atoms and so on, as you would when you literally heat it up, increase its temperature. One of the things that can happen then is that the the electrons in the atom can get pushed into higher energy levels, excited states. And this now requires, to do it properly, requires so called quanto milatry dynamics, a quantum field theory. But you can so approximate it with ordinary quanto mechanics.