Question

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

• A. $3.4\text{eV}$
• B. $6.8\text{eV}$
• C. $13.6\text{eV}$
• D. $27.2\text{eV}$

Answer 1

The correct option is A $3.4\text{eV}$

Energy of electron in $n^{th}$ state of Hydrogen atom
$E=\frac{-13.6}{n^2}\text{eV}$
Energy of electron in second excited state
$E_2=\frac{-13.6}{(2{)}^2}=-3.4\text{eV}$
Thus $3.4\text{eV}$ energy is required to remove an electron from second orbit