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

Correct Answer: 6

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:

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