Question

Electrons with energy 12 eV are shot into a gas
of hydrogen atom in the ground state. How many
different wavelengths will be emitted out from this
gas sample in Balmer series?
(a) One
(b) Two
(c) Three
(d) Zero​

Answer 1

Answer:

Explanation:

In ground state  electrons have energy -13.6 eV if it absorbs 12.75 eV it have energy -0.85 eV  or it reaches in fourth 3rd excited state because third exicted state have energy -0.85 eV .

on de-excitation it shows given transition  

1. 4→1 transition

2. 4→2  transition

3. 4→3 transition

4. 3→1  transition

5. 3→2  transition

6. 2→1  transition

but according to question in emission spectra contains no line of Balmer series so 2nd and 5th transition is not taken and only four transition is possible