Question

Find the radius and speed of an electron in the ground state of doubly ionized lithium and compare them with the radius and speed of the electron in the ground state of the hydrogen atom.

(Li++ has a nuclear charge of 3e.)

Answer 1

The radius of the orbit of the electron in the ground state of the hydrogen atom is 5.29·10^-11.

For lithium, it is

$$r_n=\frac{n^2}{Z}a_B=1.76·10^{-11}\text{ m}.$$

The velocity is

$$v=\frac{nh}{2mr\pi}=6.58·10^6\text{ m/s}.$$