Physical character of the wave functions

Recall that a classical electron has a stable orbit around the nucleus when we neglect electromagnetic radiation effects. The wave functions $\psi_{nlm}(r,\theta,\phi)$ of the electron are, therefore, called orbitals. However, do not confuse these with trajectories or anything else dynamic. These are complete static objects that only give static probabilities when the electron has a well-defined allowable energy.

The shapes of the orbitals are largely determined by the values of angular momentum, so we will characterize the orbitals this way.