Atomic Structure in Quantum Mechanics

Bohr arrived at these "stationary states" by requiring a quantization of the angular momentum.

If we look at the deBroglie wavelength of an electron for these various energies, we find that it "fits" the allowed orbits with an integral number of wavelengths--leading to constructive interference much like standing waves on a rope.

But a better picture is that of an "electron cloud" surrounding the nucleus with the "density" of the cloud connected to the probability of finding the electron.

Energy is quantized. The n in En is called the principal quantum number.

So are other quantities.

Angular Momentum

is called the orbital quantum number.

z-compent of angular momentum

is called the magnetic quantum number.

The intrinsic angular momentum of the electron, often call the electron's spin, is

The z-component of the spin of the electron is

 

Atomic Energy Levels

Complex Atoms

Return to Ch 29, Atomic Physics

(c) Doug Davis, 1997; all rights reserved