Postulate 1.electrons can revolve around the nucleus only in certain "allowed orbits" and while in this orbits they do not emit radiations. postulate 2.for circular motion,the allowed orbits are determined by the quantum condition that the angular momentum is in postulate 3.energy changes can only occur from one energy level to another and not between levels
lily nekesa answered the question on November 13, 2017 at 12:05
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