Find the radius and energy of a `He^(++)`ion in the states (a) `n = 1 , (b) n = 4 and (c) n= 10` is

Answer

A, B, C, D

Explanation

(a) Here `n=1`, `r=(in_0h^2n^2)/(pimZe^2)`
`=(0.53n^2)/(z)A^@`
`epsilon = (-13.6Z^2)/(n^2) = (-13.6 xx 4)/(1)`
`=-54.4 eV`
(b) `n=4`, `r=(0.53 xx 16)/(2) = 4.24 A^@`
`epsilon = (-13.6 xx 4)/(164) = -3.4 eV`
(c) `n=10`, `r=(0.53 xx 100)/(2)`
`=26.5 A^@`
`epsilon = (-13.6 xx 4)/(100) = -0.544 eV`