Which of the following transition will have a wavelength different than that observed in rest of the transition ?

Options

A. H-atoms, transition from `3^(rd)` level to `1^(st)` level.
B. `He^(+)` ion, transition from `5^(th)` excited state to `1^(st)`
C. `Li^(2+)` ion, transition from `9^(th)` level to `3^(rd)` level.
D. `Be^(+3)` ion, transition from `11^(th)` excited state to `3^(rd)` level

Answer

D

Explanation

(A) `1/(lambda_(H))=Rxx1^(2)(1/(1^(2))-1/(3^(2)))`
(B) `1/(lambda_(He^(+)))=Rxx2^(2)(1/(2^(2))-1/(6^(2)))`
(C) `1/(lambda_(Li^(2+))=Rxx3^(2)(1/(3^(2))-1/(9^(2)))`
(D) `1/(lambda_(Be^(3+))=Rxx4^(2)(1/(3^(2))-1/(12^(2)))`
D is different