When an electron drops from a higher energy level to a low energy level then
Energy is emitted in the form of Photon
Energy is absorbed in the form of Photon
atomic number increases
atomic number decreases
When an electron de excites from a higher energy level to a lower energy level, the difference in energy is emitted in the form of a photon.
There is no change in atomic number of an atom due to excitation or de excitation of electron as the atomic number is the number of protons present inside the nucleus