(1) The radius of the allowed electron orbits is determined by Quantum condition which states that the orbit angular momentum of the electron about the nucleus is an integral multiple of h/2π. According to Bohr’s postulate
mvr = nh/2π ------ (1)
(2) The atom radiates energy only when an electron jumps from one stationary orbit of higher energy to another of lower energy
E2 – E1 = hν or ν = (E2 – E1)/h.
