atom		particle that has no charge (neutral)
proton		place in an electron cloud when an electron is most likely found
neutron		Total # of protons & neutrons in an atom
electron		center of an atom
nucleus		smallest part of an element
energy level		anything that has mass and takes up space
matter		# of protons in the nucleus of an atom
atomic mass		Capital letter(s) that represent substances on periodic table
atomic number		atomic particle with a positive charge
element symbol		atomic particle with a negative charge