What orbits the nucleus of an atom?

Particle-like properties: The number of electrons orbiting the nucleus can only be an integer. Electrons jump between orbitals like particles. For example, if a single photon strikes the electrons, only a single electron changes states in response to the photon. read more

Actually, we used to think that they orbit, like planets in the solar system, but they’re actually so fast that they obey the rules of quantum mechanics. So we can’t predict where they’ll be at any one time, but instead there are certain patterns around the nucleus, called orbitals, in which, somewhere, the electrons are whizzing about. read more

In quantum mechanics, an atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. read more