The total energy of an electron in the n ^ th stationary orbit of...

Bohr’s Postulates are as follows: The electron revolves around the nucleus at stable orbits without radiating energy. The stable orbits are called stationary orbits. These orbits are unique and have different radii. The electron cannot orbit in between two stationary orbits, meaning the orbits are uniquely determined. The stationery orbits are obtained by equating the angular momentum of the electron to an integral multiple of reduced Planck’s constant, $mvr = \dfrac{nh}{2\pi}$, where $v$ is the velocity of the electron in the nth orbit and $r$ is the radius of the ${n}^{th}$ orbit. The orbits have definite energies called the energy shells or energy levels. For hydrogen, ${E}_{n} = - \dfrac{13 . 6}{{n}^{2}}eV$.