What is an atomic nucleus? the outer part of an atom in which electrons move the outer part of an atom in which neutrons move the central part of an atom, composed of protons and neutrons the central part of an atom, composed of protons and electrons
An atom is composed of two regions: the nucleus, which is in the center of the atom and contains protons and neutrons, and the outer region of the atom, which holds its electrons in orbit around the nucleus.