A gas of monoatomic hydrogen is bombarded with a atream of electrons that have been accelerated from rest through a potential difference of `12.75 V`. In the emission spectrum, one can observe lines of

Options

A. Lyman series
B. Balmer series
C. Paschen series
D. Pfund series

Answer

A, B, C

Explanation

`E_(n)^(H) = E_(1)^(H) + Delta E = - 13.6 eV + 12.75 eV = - 0.85 eV` , i.e., hydrogen atom are excite to `n = 4` level, i.e., transitions `4 to 1, 3 to 1, 2 to 1` are possible which corresponds to Lyman series, then transitions `4 to 2 and 3 to 2` are possible which corresponds to Balmer series and then transitions `4 to 3` is also possible which correspond to Pachen series.