The ratio of the radii of first orbit of H, He+ and Li2+ is?

1 Answer
Jun 13, 2017

The radii are in the ratio #6:3:2#.

Explanation:

The radii of the first orbits of a hydrogen-like ion are given by the equation

#r = (ħ^2)/(Zm_ek_ee^2)#

Since everything except #Z# is constant, we can rewrite the formula as

#r = k/Z#

Then the ratios of the three radii for #Z = 1, 2# and #3# are

#r_1:r_2:r_3 =1/1:1/2:1/3 = 6:3:2#