Kinetic orbital momentum

1. Sep 15, 2007

C_Ovidiu

In some places I saw that the module of the kinetic orbital momentum of an electron in an atom is
a) L^2=l(l+1)h^/(4pi^2) ==> L =h/(2pi)sqrt(l*(l+1)) l=0,1,2,....n-1
b) L=n*h/(2pi)
n beeing the energy level of an electron .

Now , my opinion is that the first is true . But I saw some problems solved using only the second value . I'm really confused . Which one is it ?
Thank you !

2. Sep 15, 2007

dextercioby

Well, the first equation comes from the angular momentum theory in quantum mechanics, while the second is nothing but one of Bohr's postulates in his 1913 theory of the hydrogen atom.

Do you see what the difference is really about ?

Last edited: Sep 15, 2007
3. Sep 15, 2007

C_Ovidiu

Tks .
There are lots of differences .