Question

the ratio of the radii of the 5th orbit of he+ and li+ will be

Answer 1

The formula for the radius in an orbit is r =0.53n²/z where n is the orbit no. and z is the atomic no of the element.

first take out the radius of 5th orbit of he+ by 0.53 x (5)² / 2

then take out the radius of 5 th orbit of li+
0.53 x (5)² / 3

then take the ratio of radius of he+ / li+
= 3:2
the answer is 3:2