question_answer

A gas of identical hydrogen like atoms has some atoms in the lowest (ground) energy level A & some atoms in a particular upper (excited) energy level B & there are no atoms in any other energy level. The atoms of the gas make transition to a higher energy level by the absorbing monochromatic light of photon energy\[2.55\text{ }eV\]. Subsequently, the atoms emit radiation of only six different photon energies. Some of the emitted photons have energy\[2.55\text{ }eV\]. Some have energy more some have less than\[2.55\text{ }eV\]. Find the principle quantum number of the initially excited level B.

Answer:

2.00