Atoms And Nuclei Question 93
Question: If R is the Rydberg’s constant for hydrogen the wave number of the first line in the Lyman series will be [KCET 2000]
Options:
A) $ \frac{R}{4} $
B) $ \frac{3R}{4} $
C) $ \frac{R}{2} $
D) 2R
Show Answer
Answer:
Correct Answer: B
Solution:
For Lyman series $ \bar{\nu }=\frac{1}{\lambda }=R,( \frac{1}{1^{2}}-\frac{1}{n^{2}} ) $ here n=2, 3, 4, 5….. For first line $ \bar{\nu }=R,( \frac{1}{1^{2}}-\frac{1}{2^{2}} )\Rightarrow \bar{\nu }=R,( 1-\frac{1}{4} )=\frac{3R}{4} $
