Thanks for the complete explanation.
I realize that we think and observe the world in a high level, rather illusionary perception and the world of particles seems mindblowing, with puzzles the like of old Resident Evil games. Something that crossed my mind today; the elements could become...
So (usually) it is the proton and neutron (or just nuclei as a whole?) who emit photons - stimulated by the movement of the electron when the electron changes orbits.
And how does the nuclei absorb foreign travelling photons? Also I guess the 'electron emits photons' is an outdated allegorical...