Atom the smallest component of an element that still has properties of the element, consisting of a positively charged nucleus surrounded by a charged cloud of electrons. Neutron a non-charged nuclear particle with the same mass as the proton. Isotope atoms with the same number of protons and electrons, but different numbers of neutrons. A cartoon of atoms. Electrons are outside the nucleus, and determine properties of the atom.
Electrons determine chemical properties of elements.
Chemical reactions involve sharing or exchanging electrons. Electrons move about the nucleus in atomic orbitals. Absorption of energy can cause an electron to move up to a higher energy level. The atom is stable when the outermost energy level of most atoms has eight electrons. Electrons can be transferred carrying energy to another molecule.