12 eV energy is given to electron in third orbit of H -atom, then final energy of electron when it ionise from third orbit, is

Step-by-step solution

Given, total energy given to electron in third orbit, E = 12   eV Energy of third orbit of H -atom, E ' = - 13 . 6 n 2 = - 13 . 6 3 2 = - 1 . 51   eV lonisation energy of electron of third orbit, E ' ' = - E ' = - - 1 . 51   eV ⇒ E ' ' = 1 . 51   eV Hence, final energy of electron when it comes out of H -atom from third orbit E f = E - E ' ' = 12 - 1 . 51 = 10 . 49   eV