Question

In a H-like sample electrons make transition from $4^{th}$ excited state to $2^{nd}$ state then

• A. 10 different spectral lines are observed
• B. 6 different spectral lined are observed.
• C. number of lines belonging to the balmer series is 3
• D. number of lines belonging to the Paschen series is 2

Answer 1

Answer: (B), (C), (D)

The correct options are
B 6 different spectral lined are observed.
C number of lines belonging to the balmer series is 3
D number of lines belonging to the Paschen series is 2

Transition is taking place from $5\to 2$
$⟹\Delta n=3$
Hence maximum number of spectral line observed=$\frac{3(3+1)}{2}=6$
(C) Number of lines belonging to the balmer series=3
(D) Also we can see that number of lines belonging to paschen series.