Question

Calculate the radius of first two orbits of $Li^{2+}$?

Answer 1

In order to calculate the radius of the first two orbits of Lithium ion, we can use the Bohr’s atomic model theory and its postulates.

The Bohr's atomic theory and its postulates are valid only for single electron species or hydrogen like species like Hydrogen, $He^{+}$, $Li^{2+}$ and so on.

$Li^{2+}$ has only one electron, we can apply the following formula and find the radius,

Radius of 1st orbit, n = 1

Z = 3 for Li,

$r=0.529\times \frac{n^2}{z}$A°

$r_1=0.529\times \frac{1^2}{3}$= 0.1763A°

$r_2=0.529\times \frac{2^2}{3}$= 0.7053A°