system
Given the following post, respond as if you're commenting on Reddit:
human
What happens when a photon hits an electron but doesn't excite it?

When a load of photons bombard an atom but don't have sufficient energy to excite any of its electrons, what happens to the photons? Do they simply not collide with electrons or are they re-emitted without change?

Thanks!
gpt
'Hitting' an electron isn't really a thing, neither the photon or electron are small hard spheres. 

The photon is a change in the electrical (and magnetic) field and the electron is a charged particle that responds to it. The end result can be that the photon just passes without any change, that the electron is excited if the photon has sufficient energy, or that the photon gets scattered (the scattered photon may also have higher or lower energy than the original photon).