Four Types of Atomic Orbitals

S Orbital

• The S orbital, which is spherical, is the most basic orbital. There is room for two electrons in this orbital, which are represented on the periodic table in the alkali and the alkaline earth metals. In addition, hydrogen and helium fill the S orbital, as they do not have more than two electrons. The S orbital is the only orbital type that has an anti-node at the center of the nucleus. All other orbitals avoid the nucleus due to a wave node at the nucleus that causes angular momentum away from it.

The P Orbital

• The next orbital type is the P orbital, which has a perpendicularly oriented triple dumbbell shape. Each dumbbell lobe is oriented in the six principle directions in three-dimensional space. The dumbbells have their point of tangency at the nucleus. There is room for six electrons in the P orbitals. The P orbital corresponds to the post transition metals, metalloids, nonmetals, halogens and noble gases on the periodic table.

The D Orbital

• The D orbital has five separate lobes. Four of the lobes are composed of pear-shaped bulbs that lie in a plane with their tangential point at the nucleus. These lobes occupy the three principal three-dimensional planes as well as one tangential plane. The final lobe is composed of a torus with two pear-shaped bulbs on the z-axis. There is room for 10 electrons in the D orbital, which correspond to the transition metals.

The F Orbital

• The F orbital has seven separate lobes arranged in a very complicated shape. The F orbital has enough space for 14 electrons, which correspond to the lanthanides and actinides of the inner transition metals.

Theoretical Orbitals

• There is technically a fifth type of orbital as well. This fifth orbital refers to larger, theoretical orbitals which hold the electrons for theoretical elements.