Why does the energy of an electron does not change with time ?
Fact that I am answering your post is based on electrons changing their energies, both in my body, in my monitor, and in zillions of devices between you and me. So your question is either completely wrong, or it is incomplete (ie it doesn't state conditions in which the energy doesn't change).
It doesn't change with respect to time.But the energy does change when the electron moves from either lower to higher or higher to lower energy levels (stationary orbits).It leads to either emission or absorption of spectrum of colors.which are quantisied.
Sure it does. If it changes at all (and it does) it must change in time.
I have no idea what you are aiming at, sorry.
It's okay.Don't worry about it
I get too many stupid doubts as soon as I get to read about something.
Separate names with a comma.