Question

The energy required to excite an electron of H-atom from first orbit to third orbit is​

Answer 1

Electrons in a hydrogen atom must be in one of the allowed energy levels. If an electron is in the first energy level, it must have exactly -13.6 eV of energy. If it is in the second energy level, it must have -3.4 eV of energy.

here is your answer!

hope it helps you ♡´･ᴗ･`♡