1. Binary Covalent Compounds
►Binary Covalent compounds are composed
of 2 non metals.
►When 2 non-metals combine, they often do so in more than one way.
Ex. CO, CO2, NO, NO2, N2O5
►If you use the rules for ionic compound nomenclature, the name for all the above examples would be the same.
►Prefixes help to distinguish between different compounds.

2. Binary Covalent Compounds Prefixes
– mono
– di
– tri
– tetra
– penta
– hexa
– hepta
– octa
– nona
- deca

3. Writing Formulas for Binary Covalent Compounds
►Write the symbol of the first element.
►Write the number for the prefix as a subscript to the right of the element symbol.
►Write the symbol of the second element.

4. SF6 Examples CCl4 N2 O ►Carbon tetrachloride ►Dinitrogen monoxide
►Sulfur hexafluoride
N2 O
SF6

5. Naming Binary Covalent Compounds
►Look at the subscript of the first element.
Write the prefix of that number.
►Attach the name of the first element to the prefix.
►Look at the subscript of the second
element. Write the prefix of that number.
►Attach the root of the second element and
add –ide as a suffix.
►If the prefix is mono for the first element, you may omit the prefix.

6. Examples Arsenic trichloride Carbon monoxide Tetraphosphorus decoxide
►AsCl3
►CO
Carbon monoxide
►P4O10
►NF3
Tetraphosphorus decoxide
Nitrogen trifluoride