Question

4. Which of the following transitions of an electron in a hydrogen atom corresponds to the lowest frequency of the emitted photon? (n = 2 → n = 10 means a transition from the state with n = 2 to the state with n = 10)

(A) n = 4 → n = 2

(B) n = 5 → n = 3

(C) n = 4 → n = 5

(D) n = 6 → n = 3

(E) n = 5 → n = 2

Answer 1

For emission, electron moves from higher energy state to lower energy state.

So, C is not emission.

For lowest frequency, energy difference between value of n should be lowest.

Since as value of n increases, energy difference between subsequent shell decreases, so energy difference will be minimum in case of B

So, B would have lowest frequency
Answer: B