Question

The energy required to escape the electron from ground state of $H$ is $13.6$ eV. Then the same for $1^{st}$ excited state of $H-$atom is:

• A. $3.4$
• B. $13.6$
• C. $27.2$
• D. can't say anything.

Answer 1

Answer: (A)

$3.4$

According to the problem:-

$E_n=\frac{-13.6}{n^2}eV$

1st excited state$\left(n=2\right)$

$E_n=\frac{-13.6}{{\left(2\right)}^2}=-3.4eV$