The radius of the forst Bohr orbit of hydrogen atom is `0.59 Å`. The radius of the third orbit of `He^(+)` will be

Options

A. `8.46 Å`
B. `0.705 Å`
C. `1.59 Å`
D. `2.38 Å`

Answer

D

Explanation

`r_(n) = (a_(0) n^(2))/(Z) = (0.59 B208Å xx 3^(2))/(2) = 2.38 B208Å`