Atoms - Result Question 16
17. Hydrogen atom in ground state is excited by a monochromatic radiation of $\lambda=975 \AA$. Number of spectral lines in the resulting spectrum emitted will be
[2014]
(a) 3
(b) 2
(c) 6
(d) 10
Show Answer
Answer:
Correct Answer: 17. (c)
Solution:
- (c) For the $\lambda=975 \AA$
$ \frac{1}{\lambda}=R(\frac{1}{n_1^{2}}-\frac{1}{n_2^{2}}) $
where $R$ is the Rydberg constant
Solving we get $n_2=n=4$
( $\because n_1=1$ ground state)
Therefore number of spectral lines
$=\frac{n(n-1)}{2}=\frac{4(4-1)}{2}=6$
