How do electrons behave as both particles and waves?

Electrons exhibit both particle and wave properties, a phenomenon known as wave-particle duality. Rather than being strictly one or the other, an electron is an object that manifests these properties depending on the specific measurement being performed.12

Wave-Like Behavior

The wave nature of electrons is evidenced by experiments such as the electron-counterpart to Young’s experiment. When electrons pass through two narrow slits, they create an interference pattern on a detector, similar to light waves. This behavior is described by the de Broglie formula, which assigns a wavelength to particles based on their momentum. In atoms, these wave properties are represented by wave functions, where electrons exist in specific configurations called orbitals.234

Particle-Like Behavior

Conversely, electrons demonstrate particle properties when they are detected at a specific, localized point in space. While the wave function predicts the probability of where an electron might be found, the actual detection is a discrete event characteristic of a particle.2

Complementarity

According to the complementarity principle, these aspects are mutually exclusive in a single measurement. For instance, attempting to determine which slit an electron passes through destroys the interference pattern, forcing the electron to behave as a particle. This fundamental limitation is also reflected in the Heisenberg uncertainty principle, which states that one cannot simultaneously measure the precise position and momentum of a particle.125