If the following atoms and molecylates for the transition from `n = 2` to `n = 1`, the spectral line of minimum wavelength will be produced by

Options

A. Deuterium atom
B. Doubly ionized lithium
C. Hydrogen atom
D. Singly ionized helium

Answer

B

Explanation

For the transition , n=2 to n =1, the wave number of the spectral line is given by
`1/lamda = RZ^2 ((1)/(1^2) - (1)/(2^2)) " or " lamda prop 1/Z^2`
`therefore` Out of the given atoms and molecules , A is maximum for lithium (Z =3). Hence the wavelength is minimum.