Quantum number area assigned to get complete inforamtion of electrons regarding their energy engular momentum ,spectral lines etc. Four quantum number are known i.e pricipal quantum numbers which tell the diatence shell and its angular momentum .Azimuthal and of courase shape of orbital , Magnetic qunatum number deals with syudy of orientations or deganeracy of a subshell . spin quantum number defines te spin of electrons designaated as `+(1)/(2) or-(1)/(2)` respresented by 123 and 123 respectively .
Electrons are filled in oritals and Hun's rule of maximum multicity .
spin angular momentum for unpaires electron in sodium (Atomic No =11 ) is :

Options

A. `sqrt(3)/2`
B. `0.866 h//2pi`
C. `-sqrt(3)/2 h/(2pi)`
D. None of these

Answer

B

Explanation

`sqrt(s(s+1))h/(2pi)=sqrt(1/2(1/2+1))h/(2pi)=sqrt(3)/2h/(2pi)=0.866 h/(2pi)`