Question

Which of the following is/are the energy of an excited state of hydrogen?

• A. -13.6 eV
• B. -6.8 eV
• C. -3.4 eV
• D. +6.8 eV

Answer 1

Answer: (A), (C)

The correct options are
A -13.6 eV
C -3.4 eV

$E=-13.6Z^2/n^2$
Keep in mind that n has to be an integer.
Substitute n = 1, we get -13.6 eV as the energy
Substitute n = 2, we get -3.4 eV as the energy
Substituting any value of n, we cannot get energy as -6.8 eV or +6.8 eV.