If the electron of a hydrogen atom is present in the first orbit, the total energy of the electron is

If the electron of a hydrogen atom is present in the first orbit, the total energy of the electron is
  1. $\frac{-e^2}{r}$
  2. $\frac{-e^2}{r^2}$
  3. $\frac{-e^2}{2 r}$
  4. $\frac{-e^2}{2 r^2}$

Solution

\(\begin{aligned}
& E_{\text {total }}=P \cdot E+K E \\
& P E=\frac{-z l^2}{r} \quad k E=\frac{z e^2}{2 r} \\
& \text { for } H \text {-atom }, \quad z=1 \\
& E_{\text {Total }}=\frac{-e^2}{r}+\frac{e^2}{2 r}=\frac{-e^2}{2 r}
\end{aligned}\)
Answer: option-3

Asked in: JEE-TOPICTESTS-CHEMISTRY

Practice more STRUCTURE OF ATOM questions on Aicharya