Question

The ionisation potential of a hydrogen atom is $13.6volt$. The energy required to remove an electron from the second orbit of hydrogen is:

• A. $3.4eV$
• B. $6.8eV$
• C. $13.6eV$
• D. $27.2eV$

Answer 1

Answer: (A)

$3.4eV$

Energy required to remove electron in the $n=2$ state

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

$\Delta E=-13.6[\frac{1}{{\infty }^2}-\frac{1}{4}]$

$\Delta E=\frac{13.6}{4}eV$

$=3.4eV$