Q. The ground state energy of hydrogen atom is −13.6 eV. When its electron is in the first excited state, its excitation energy is
A) 0
B) 3.4 eV
C) 6.8 eV
D) 10.2 eV
Explanation
[Solution from source] The first excited state is n = 2 with energy −13.6/4 = −3.4 eV. Excitation energy = −3.4 − (−13.6) = 10.2 eV. 3.4 eV is the energy needed to ionise from n = 2, not the excitation energy from the ground state. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.