Electrons move around the atomic nucleus.
An atom contains protons, neutrons, and electrons, electrons being the one that moves around the nucleus. The other two are in the nucleus.
an electron
Assuming that's the nucleus of an atom, the answer is "electrons". They are in "clouds", sort of, around the nucleus of atoms.
Elements do not move around the nucleus since the nucleus is at the core of the element.
The negatively charged subatomic particle that moves around the nucleus is the electron. The proton, along with the neutron, comprises the nucleus.
electrons
electron cloud
Electron(s)
electron
ROFLCOPTER
The electron