Question

What should be the emitted energy when the electron present in hydrogen atom jumps from $n=4$ to $n=2$?

• A. $4.08\times {10}^{-19}$ Joule
• B. $5.4\times {10}^{-19}$ Joule
• C. $21.79\times {10}^{-19}$ Joule
• D. $3.2\times {10}^{-19}$ Joule

Answer 1

The correct option is A $4.08\times {10}^{-19}$ Joule

$\text{Energy,}[E=13.6[\frac{1}{n_1^2}-\frac{1}{n_2^2}]\text{ev}]$

$\begin{array}{cc}{n}_2& =2,n_1=4\\ E=& 13.6\left[\frac{1}{4}\frac{1}{16}\right]\\ E& =13.6\left[\frac{3}{16}\right]\text{ev}\\ & =3.4\times \frac{3}{4}\times 1.6\times {10}^{-19}J\\ E& =4.08\times {10}^{-19}\text{Joule}\end{array}$