Atoms And Nuclei Question 90
Question: What will be the angular momentum of a electron, if energy of this electron in H-atom is 1.5eV (in J-sec) [RPMT 2000]
Options:
A) $ 1.05\times {{10}^{-34}} $
B) $ 2.1\times {{10}^{-34}} $
C) $ 3.15\times {{10}^{-34}} $
D) $ -2.1\times {{10}^{-34}} $
Show Answer
Answer:
Correct Answer: C
Solution:
Energy of electron in H atom $ E_{n}=\frac{-13.6}{n^{2}}eV $
$ \Rightarrow -1.5=\frac{-13.6}{n^{2}}\Rightarrow n^{2}=\frac{13.6}{1.5}=3 $
Now angular momentum $ p=n\frac{h}{2\pi }=\frac{3\times 6.6\times {{10}^{-34}}}{2\times 3.14}=3.15\times {{10}^{-34}}J\times \sec $
