The total energy (sum of kinetic and electrostatic potential) of
| The total energy (sum of kinetic and electrostatic potential) of the electron in a hydrogen atom is ______________.
A. -e<sup>2</sup>/(4πϵ<sub>o</sub>r)
B. -e<sup>2</sup>/(8πϵ<sub>o</sub>r<sup>2</sup>)
C. -e<sup>2</sup>/(4πϵ<sub>o</sub>r<sup>2</sup>)
D. -e<sup>2</sup>/(8πϵ<sub>o</sub>r)
Please scroll down to see the correct answer and solution guide.
Right Answer is: D
SOLUTION
CONCEPT:
- Potential energy: An electron possesses some potential energy because it is found in the field of nucleus potential energy of an electron in nth orbit of radius rn is given by
\(U = - \frac{{{e^2}}}{{4\pi {\epsilon_0}r}}\)
Where r = radius and e = charge on the electron
- Kinetic energy: Electron possesses kinetic energy because of its motion.
- Closer orbits have greater kinetic energy than outer ones.
\(K =\frac{{{e^2}}}{{8\pi {\epsilon_0}r}} \)
EXPLANATION:
- Total energy: Total energy (TE) is the sum of potential energy and kinetic energy i.e.
⇒ E = K + U
\(\Rightarrow E=\frac{{{e^2}}}{{8\pi {\epsilon_0}r}} - \frac{{{e^2}}}{{4\pi {\epsilon_0}r}} = \; - \frac{{{e^2}}}{{8\pi {\epsilon_0}r}}\)
- Therefore, the total energy of electron in orbit of the hydrogen atom is negative.
- Hence, the electron is bound to the nucleus, i.e., the electron is not free to leave the orbit around the nucleus.