Naming Compounds

Binary Ionic Compounds

Binary compounds contain only two elements (prefix bi means two…like bicycle)

Remember an ionic compound is between a metal and nonmetal. When naming, simply state the name of the metal first, then the nonmetal, changing the ending to –ide

NaCl = sodium chloride

Molecular (covalent) compoundsName the first element, then change the ending of the second element to –ide

NBr = nitrogen bromide

Molecular compounds with multiple atomsYou must use prefixes to show the number of atoms in each element

Number of Atoms Prefix

1 mono-

2 di-

3 tri-

4 tetra-

5 penta-

6 hexa-

7 hepta-

8 octa-

9 nona-

10 deca-

Examples

NO2 nitrogen dioxide

(the prefix mono is not used on the first element in the compound)

N2O4 dinitrogen tetraoxide

Polyatomic Ions

NH4+ Ammonium

OH- Hydroxide

NO3- Nitrate

SO42- Sulfate