The orbital angular momentum of an electron in 2s orbital is?(IIT 86)

a) +1/2 h/2 pi

b)zero

c)h/2 pi

d) 2^1/2 h/2 pi

yeah it's the right ans.....thanx..............

 orbital angular momentum is given by [{l(l+1)} ^ 0.5]* (h/2 pie)...................here l= azimuthal quantum no. ,,,and l is zero for the s orbital .....hence orbital angular momentum of the 2s orbital is also zero!!!!!!!!!!

 okay ,so here another approach (conceptual)

the 2s is electron is revolving about the nucleus ...and thus must definitely have an angular momentum  i.e I(omega)...

then why is da answer 0?????

ok den.........

let us suppose the electron is orbiting in the x-z plane in anticlock wise direction so the angular momentum is in +y direction......

if for u  the electron revolves in the x-z plane then for meit is in the y-z or any other plane ...as u cannot specifically say that it revolves in this particular plane..................

hence ,summation(vectorial addition as angular momentum is a vector) of all these angular momentum in different directions gives net 0..

it clearly happens in case of s orbitals bcoz of spherical symmetry..............

hope u understood! 

B . Zero