Question

please answer this question​

Answer 1

n=1

E= -13.6ev

change in energy =-13.6+12.75= - 0.85

En=. 0.85

-0.85= -13.6*1^2/n2

by simplifying we get n=4

or

E4=-13.6*1/4²= -13.6/16 = -0.85

Thus n=4