H2, N2, O2, F2, Cl2, Br2, and I2
Allotropes – Elemental molecules with different formulas. i.e. O2 and O3
Ionic compounds – metal and nonmetal (can be polyatomic too)
Molecular compounds – two or more nonmetals
Naming ionic compounds
1. Name the metal.
2. Write the metal’s oxidation state as a Roman numeral in parenthesis.
3. Name the nonmetal using an “ide” ending
Ex. Iron (II) Chloride, FeCl2