Question

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 decreases
• B. Its kinetic energy decreases, potential energy increases and its total energy remains the same
• C. Its kinetic and total energies decreases and its potential energy increases
• D. Its kinetic, potential and total energies decrese

Answer 1

The correct option is A Its kinetic energy increases and its potential and total energies decreases

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 $K_n=|E_n|=13.6\frac{z^2}{n^2}eV$

From these three relations we can see that as $n$ decreases, $K_n$
will increase but $E_n$ and $U_n$ will decreases.