Which of the following species will produce the shortest wavelength for the transition `n = 2 "to" n= 1` ?

Options

A. Hydrogen atom
B. Singly ionised helium
C. Deuterium atom
D. Dioubly ionised lithium

Answer

D

Explanation

Shortest `lambda` will be produced in the ion, which has high Z value
`Z` for `H_(2) ^(o+) = 1, Z `"for" `H ^(o+) = 2`
` Z`" for" `D = 2, Z "for" Li^(2+) = 3`