The wave nature of electrons is fundamental to chemistry. Atomic orbitals and chemical bonds both correspond to standing waves formed by electrons, so it is important to have some sense of what a standing wave represents and how they behave. Here are some videos demonstrating standing waves.

There are some common threads in all standing waves.

• Nodes – points where the wave has zero amplitude – can have different geometries. They can be lines, circles, or more complicated curves.
• There are only certain energies that a standing wave can have. This depends on the mechanical properties of the system (e.g. for the drumhead, the thickness and elasticity of the material and how tightly it is drawn).
• In general, the number of nodes increases as the energy of the wave increases.