For the third electron of Lithium atom moving in its premissible orbit, the values of angular momentum and energy are...... Respectively

Options

A. Angular momentum `(h)/(2pi)` energy `=(-9pi^(2)e^(4)m)/(2h^(2)`
B. Angular momentum `(3h)/(2pi)` energy `=(+3pi^(2)em^(4))/(4h^(2)`
C. Angular momentum `(h)/(2pi)` energy `=(3pi^(2)me^(4))/(2h^(2)`
D. Angular momentum `(h)/(2pi)` energy `=(-6pi^(2)e^(4)m)/(3h^(2)`

Answer

A

Explanation

`Li 1s^(2)2s^(1)`
third electron of Li means `2s^(1)`
`therefore` angular momentum quantum no = l =0 angular momentum of electron in any orbital
according to bohr equation `E=(2e^(4)pi^(2)z^(2)m)/(n^(2)h^(2))`
for third electron of li `1s^(2) 2s^(1)`
`=-9/2 (e^(4)pi^(2)m)/(h^(2))`