Correct order of radius of the first orbit of `H, He^+, Li^(2 +), Be^(3 +)` is :

Options

A. `H gt He^+ gt Li^(2 +) gt Be^(3 +)`
B. `Be^(3 +) gt Li^( 2 +) gt He^+ gt H`
C. `He^+ gt Be^( 3+) gt Li^(2 +) gt H`
D. `He^+ gt H gt Li^(2 +) gt Be^(3 +)`

Answer

A

Explanation

(a) `r prop ((n^2)/(Z))`as `Z` increases, radius of `I` orbit decreases.