Consider the spectral line resulting from the transition `n = 2 rarr n = 1 ` in the atoms and ions given . The shortest wavelength is produced by

Options

A. hydrogen atom
B. deuterium atom
C. singly ionization helium
D. doubly ionized lithium

Answer

D

Explanation

We know that
`(1)/(lambda) = R z^(2) [(1)/(n_(2)^(2)) - (1)/(n_(1)^(2))] implies (1)/(lambda) prop z^(2)`
`lambda` is shortest when `1//lambda` is i.e., when `z` is big `z` is highest for lithum.