Atoms · Question 48

Maximum frequency of emission is obtained for the transition

1. n = 2 to n = 1
2. n = 6 to n = 2
3. n = 1 to n = 2
4. n = 2 to n = 6

Answer

(1) n = 2 to n = 1

Solution

∵ Emission occurs only when the electron jumps from a higher level to a lower level, so (3) and (4) are absorption transitions.

For hydrogen, E = 13.6 ( 1n12 - 1n22 ) eV and = Eh

n = 2 n = 1: E = 13.6 (1 - 14 ) = 10.2 eV

n = 6 n = 2: E = 13.6 ( 14 - 136 ) = 3.02 eV

∴ The largest energy gap, and hence the maximum frequency, is emitted in the transition n = 2 to n = 1.

Answer: (1)