Radial Distributions

Radial wave functions rely on n and l but not on m; so each of the three 2p orbitals has similar radial form. The wave functions may have negative or positive regions, but it is more instructive to look at how the radial probability distributions for the electron rely on the distance from the nucleus. They have the following characteristics.

1. Radial distributions may have various peaks, the number being equal to n-l.
2. The outermost peak is by far the largest, displaying where the electron is most probably to be found. The distance of this peak from the nucleus is a measure of the radius of the orbital, and is approximately proportional to n² (even though it depends little on l also).

Radial distributions determine the electron's energy in an atom. Like the average distance from the nucleus increases, the electron becomes less tightly bound. At smaller distances the subsidiary maxima are not important in hydrogen, but are significant in understanding the energies in several-electron atoms.