Question

The energy of the electrons in the first excited state of the hydrogen atom is -

• A. $-2.72\text{eV}$
• B. $-0.85\text{eV}$
• C. $-0.54\text{eV}$
• D. $-3.40\text{eV}$

Answer 1

The correct option is D $-3.40\text{eV}$

We know that,

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

For first excited state, $n=2$

So,

$E=-\frac{13.6}{2^2}=-3.40\text{eV}$

Hence, option $\left(D\right)$ is the correct answer.