Which one of the following cannot emit radiation and why? Excited nucleus, excited electron.

Excited electron

The concept of nuclear isomers states that when one or more nucleons occupy or cover a higher state orbit or energy level the nucleus becomes exited, it is also a metastable state. When the nucleus of an atom is an excited state decays it release energy in form of waves or commonly known as gamma rays as shown in the equation below

where

is the excited nucleus and A is the nucleus after release of energy and is the gamma radiation. Now we can see that we a nucleus is excited it release gamma radiation. In case of an electron excitation the energy release when an electron jumps to an inner orbit from outer orbit is

E is the excitation energy, h is the plank’s constant = and v is the frequency. Now the energy released in electron excitation is at a mere or. Therefore, the energy released during an excited electron is negligible in comparison to that of a nucleus excitation. Hence, an excited electron cannot emit radiation.