Matching Pairs Atomic Structure MatchingOnline version 8.5AB by Courtney Cox 1 charge of neutron 2 valence electrons 3 atomic mass = 4 charge proton 5 charge of electrons 6 Stable Atom 7 Reactive Atom 8 cloud 9 nucleus protons + neutrons center of an atom, contains protons and neutrons area surround the nucleus negative - electrons farthest from the nucleus, responsible for reactivity/bonding positive + no charge, 0 sad atom, doesn't have a full valence shell (less then 8) so it wants to bond with others happy atom! Has a full valence shell (8ve-)