posted by Erika .
Is it true that a p electron cannot have a magnetic quantum number equal to -2?
Is it also true that for the hyfrogen atom, a 3d orbital is of higher energy then a 4s orbital?
"p" is an orbital angular momentum quantum number designation. It has a magnetic dipole moment associated with it. Its value is 1 for all p orbitals. Its component along any axis can be +1, 0 or -1. Magnetic spin is a separate quantum number, and its value is 1/2 for all electrons, with components that must be either + 1/2 or -1/2 along any axis.
For hydrogen atoms, energy depends only upon the principle quantum number n, which is the number preceding the s, p, d.. etc. The higher the principal quantum number, the higher the energy. A 4s orbital thus has more energy than a 3d.