Question

The ionization energy of hydrogen atom is $13.6eV.$ The energy required to excite the electron in a hydrogen atom from the ground state to the first excited state is:

• A. $1.69\times {10}^{-18}J$
• B. $1.69\times {10}^{-23}J$
• C. $1.69\times {10}^{23}J$
• D. $1.69\times {10}^{25}J$

Answer 1

The correct option is A $1.69\times {10}^{-18}J$

We know that,$E\left(n\right)=\frac{-13.6}{n^2}So,\Delta E=E\left(2\right)-E\left(1\right)=\frac{-13.6}{{\left(2\right)}^2}+13.6=-3.4+13.6=10.2evSo,\Delta E=10.2ev=10.2\times 1.6\times {10}^{-19}J=1.69\times {10}^{-18}J$
Option A is correct.