Question

As an electron makes a transition from an excited state to the ground state of a hydrogen−like atom/ion

• A. its kinetic energy increases but potential energy and total energy decrease
• B. kinetic energy, potential energy and total energy decrease
• C. kinetic energy decreases, potential energy increases but total energy remains same
• D. kinetic energy and total energy decrease but potential energy increases

Answer 1

The correct option is A its kinetic energy increases but potential energy and total energy decrease

$K.E\propto \frac{1}{r}$
$P.E\propto -\frac{1}{r}$
$T.E\propto -\frac{1}{r}$

As electron shifts from excited state to ground state radius will decrease.

So, kinetic energy increases but potential energy and total energy decreases.