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.

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

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.

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

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.

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