Question

The first Lyman transition in the hydrogen spectrum
has AE = 10.2 eV. The same energy change is
observed in the second Balmer transition of :-
​

Answer 1

In second Balmer transition electrons comes from n=3 to n=2

Energy of 3 rd shell : 1.51eV

Energy of 2 nd shell : 3.4eV

Energy change = 3.4-1.51=1.89eV