The electron orbitals presented here represent a volume of space within which an electron would have a certain probability. For example, in a simple lowest-energy state hydrogen atom, the electrons are most likely to be found within a sphere around the nucleus of an atom. In a higher energy state, the shapes become lobes and rings. With the exception of the n = 1 orbital, all orbitals in the top row are cutaway to show the concentric spheres. For more details and a larger collection, see http://www.albany.net/~cprimus/self/orbtable.htm