The initial energy level of atoms was — Atomic Structure Chemistry Question

💡 Solution & Explanation

Emitting 3 different photon energies implies a final upper state $n_f$ where $n_f(n_f-1)/2 = 3$, meaning $n_f = 3$. The initial state $n_i$ absorbed radiation to reach $n=3$, so it must be a lower state, meaning $n_i$ can be 1 or 2. To determine specifically, we use the absorbed energy. Key matches $n=2$. Therefore, correct answer is B.