Why is Orbital Angular Momentum Quantized in Quantum Mechanics?

[Amith2006]

When I was trying to learn the reason for the Orbital angular momentum quantum number taking only whole number values, I stumbled across the wiki site on the same, which says that,

Angular momentum in quantum mechanics

In quantum mechanics, angular momentum is quantized – that is, it cannot vary continuously, but only in "quantum leaps" between certain allowed values. The orbital angular momentum of a subatomic particle, that is due to its motion through space, is always a whole-number multiple of h(bar).

If I am not wrong, it is the Orbital angular momentum quantum number which takes whole-number values and not the Orbital angular momentum itself. The magnitude of the Orbital angular momentum is in-fact,
$$\sqrt{[l(l+1)]}$$h(bar)
The link to this site is: http://en.wikipedia.org/wiki/Angular_momentum

Oh God! Sometimes even simple things create confusion...

 

[LostConjugate]

Thats correct, the orbital angular momentum itself is not measured as 0, 1, 2, 3...

The quantum number for angular momentum is the second quantum number that comes about when using 2 dimensions where angular momentum becomes a factor. There is a quantization for every dimension of space(3).