Atoms And Nuclei Question 42
Question: The ratio of the frequencies of the long wavelength limits of Lyman and Balmer series of hydrogen spectrum is [KCEE 1996]
Options:
A) 27 : 5
B) 5 : 27
C) 4 : 1
D) 1 : 4
Show Answer
Answer:
Correct Answer: A
Solution:
For Lyman series
$ {\nu_{Lymen}}=\frac{c}{{\lambda_{\max }}}=Rc[ \frac{1}{{{(1)}^{2}}}-\frac{1}{{{(2)}^{2}}} ]=\frac{3RC}{4} $
For Balmer series
$ {\nu_{Balmer}}=\frac{c}{{\lambda_{\max }}}=Rc[ \frac{1}{{{(2)}^{2}}}-\frac{1}{{{(3)}^{2}}} ]=\frac{5RC}{36} $ \ $ \frac{{\nu_{Lymen}}}{{\nu_{Balmer}}}=\frac{27}{5} $