Modern Physics 1 Question 24
21. The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statement is true?
(2000, 2M)
(a) Its kinetic energy increases and its potential and total energy decreases
(b) Its kinetic energy decreases, potential energy increases and its total energy remains the same
(c) Its kinetic and total energy decreases and its potential energy increases
(d) Its kinetic, potential and total energy decreases
Show Answer
Solution:
Potential energy
Similarly, total energy
Therefore, when an electron jumps from some excited state to the ground state, value of
Thus, finally kinetic energy will increase, while potential and total energies will decrease.
NOTE
- For hydrogen and hydrogen-like atoms
From these three relations we can see that as
- As an electron comes closer to the nucleus, the electrostatic force (which provides the necessary centripetal force) increases or speed (or KE) of the electron increases.
