Upon completion of this module, you should be able to understand what is meant by orbitals and boundary surface diagrams and recognize the shapes of orbitals in an atom. Orbitals are areas in space around the nucleus where electrons are most likely to be found. While the wave functions that describe orbitals do not provide well-defined shapes for orbitals, they do give general shapes that show where electrons are found most of the time. These general shapes are called boundary surface diagrams.