Q. The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true
A) Its kinetic energy increases and its potential and total energies decrease
B) Its kinetic energy decreases, potential energy increases and its total energy remains the same
C) Its kinetic and total energies decrease and its potential energy increases
D) Its kinetic, potential and total energies decrease
Explanation
(a) For hydrogen and hydrogen like atoms $E_{n} = - 13.6\frac{z^{2}}{n^{2}}eV$
$U_{n} = 2E_{n} = - 27.2\frac{z^{2}}{n^{2}}eV$ and $K_{n} = \left| E_{n} \right| = 13.6\frac{z^{2}}{n^{2}}eV$
From these three relations we can see that as $n$ decreases, $K_{n}$ will increase but $E_{n}$ and $U_{n}$ will decrease
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.