Question

An electron of a hydrogen atom in an excited state is having energy $E_n = -0.85 \, \text{eV}$. The maximum number of allowed transitions to lower energy levels is $\ldots$.

Answer 1

Step 1. Calculate Quantum Number n: Use the energy formula for hydrogen:

$E_n = -\frac{13.6}{n^2} = -0.85$

Solving, $n = 4$.

Step 2. Determine Number of Transitions: The number of transitions from $n = 4$ is:

$\text{No. of transitions} = \frac{n(n - 1)}{2} = \frac{4 \times (4 - 1)}{2} = 6$