on is a subatomic particle located in the center of the atom, with no charge ??? ??? ??? Electron is a subatomic particle with an electrical change of -1 found outside of the nucleus ??? ??? ??? Valence electrons the outermost electrons in an atom ??? ??? ??? Chemical symbol an abbreviation of the name of an element ??? ??? ??? Atomic number the number of protons in the nucleus of the atom ??? ???