If a photon was incident towards an atom colliding with its electron without being absorbed by it because it has less or more energy from the required, then what will happen to the Photon next? Will it reserve its energy or lose some of its energy or lose it all? If so then where that energy is gone? Is it absorbed by the electron or something else? Please explain this point and try to be simple as much as you can thank you.
This is a good question. The photon can scatter inelastically in a process called Rayleigh scattering. Or it can scatter elastically in a process called Compton scattering.