Question

Whenever a hydrogen atom emits a photon in the Balmer series, 

(a) it may emit another photon in the Balmer series 

(b) it must emit another photon in the Lyman series 

(c) the second photon, if emitted, will have a wavelength of about 122 nm 

(d) it may emit a second photon, but the wavelength of this photon cannot be predicted

Answer 1

Correct Answer is: (b, c)

Any transition causing a photon to be emitted in the Balmer series must end at n = 2. This must be followed by the transition from n = 2 to n = 1, emitting a photon of energy 10.2 eV, which corresponds to a wavelength of about 122 nm. This belongs to the Lyman series.