1. Atom = smallest unit of an element Molecule = smallest unit of compound

2. Valence electrons The electrons in one atom that are able to form bonds with another atom. The closer the atom is to having 8 valence electrons, the more stable it is. Where are the valence electrons?

3. Covalent Bond Electrons are shared between atoms. 1 bond is when atoms share 2 electrons Nonmetal with nonmetal Neither atom is strong enough to pull an electron away from the other so they share.

4. Bonds Two atoms can form single, double or triple bonds between them. Two atoms can form no more than 3 bonds between them.