Question

Some hydrogen like atoms in ground state absorb n photons having same energy & on de-excitation they emit exactly n photons. Then the energy of absorbed photon may be:

• A. 91.8 eV
• B. 40.8 eV
• C. 48.4 eV
• D. 54.4 eV

Answer 1

Answer: (A)

91.8 eV

According to the question,

Number of dark lines during absorption= Number of bright lines during emission.

This condition is possible when electron is excited from ground state to $n=2$

So, the energy of absorbed photon may be $91.8eV$ or $40.8eV$