Q. The ground state energy of hydrogen atom is $13.6\, e V$. The energy needed To ionise hydrogen atom from its second excited state is

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A

1.51e V

B

3.4 eV

C

13.6 eV

D

12.1 eV

Solution:

For second excited state $n=3,$
$ E_{3}=13.6 / 3^{2}=13.6 / 9=1.51\, eV$

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