For orbitals that are symmetric but not spherical, the contour representations (as in Figures) suggest where nodal planes exist (that is, where the electron density is zero). For example, the px orbital has a node wherever x = 0. This equation is satisfied by all points on the yz plane, so this plane is called a nodal plane of the px orbital.

▲ Figure The p orbitals. (a) Electron-density distribution of a 2p orbital. (b) Contour representations of the three p orbitals. The subscript on the orbital label indicates the axis along which the orbital lies.

▲ Figure Contour representations of the five d orbitals.

(a) Determine the nodal plane of the pz orbital. (b) What are the two nodal planes of the dxy orbital? (c) What are the two nodal planes of the dx2 - y2 orbital?