When an electron moves from higher energy level to lower energy level the energy doesn't released. But actually it should release. What happened to the in released energy?
LookWell it doesn't move - its simply found to be in a lower energy state if you observe it. Whats going on when not observed is anyone's guess. The theory is silent on it although various interpretations have different takes on the issue.
The energy is released in a emitted photon.
I can guess your next question - what causes it to do that? Its because the electron is not strictly in a stationary state as its coupled to the quantum EM field that permeates all of space:
The phenomena is called spontaneous emission and can not be explained by standard QM - its one of the first indications you need quantum field theory:
No. Energy conservation forbids it.Look So there is no chance to be energy not release