Question

In a H-like sample, electrons make transition from $5^{th}$ excited state to $2^{nd}$ excited state. Then:

• A. 10 different spectral lines will be emitted
• B. 6 different spectral lines will be emitted
• C. Number of lines belonging to Balmer series will be 4
• D. Number of lines belonging to paschen series will be 3

Answer 1

Answer: (B), (D)

Number of lines belonging to paschen series will be 3
6 different spectral lines will be emitted

As we know, no. of emitted line will be $\frac{(n_2-n_1)(n_2-n_1+1)}{2}=\frac{(6-3)(6-3+1)}{2}=6$
And out of these six lines, three lines will belongs to paschen series.