Answer :
When an electron moves from n = 2 to n = 1, it emits a photon of ultraviolet light.
What happen in transition from n= to n=1?
During transition from n=2 to n=1 in a hydrogen atom, the electron emits energy in the form of photon. We know that when electron absorb energy, it moves from lower level to higher level and vice versa.
So we can conclude that when an electron moves from n = 2 to n = 1, it emits a photon of ultraviolet light.
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