Using Bohr's postulates for hydrogen atom, show that the total energy (E) of the electron in the stationary states can be expressed as the sum of kinetic energy (K) and potential energy (U) , where K= -2U. Hence deduce the expression for the total energy in the nth energy level of hydrogen atom.( No links please) ( This question was asked by me before but the provided by experts was not satisfactory and wouldn't understand )