In which of the following systems will the radius of the first orbit (n=1) be minimum?

Options

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

Answer

D

Explanation

Since, `r_(n)= r_(0) (n^(2))/(Z)`
`therefore r_(n) prop (1)/(Z)`
for `L^(+ +), z= 3, r_(n) rarr` lowest