Some examples of binary molecular compounds are hydrofluoric acid, written as HF; nitrogen dioxide, written as NO2; and phosphorus pentoxide, written as P2O5. A binary molecular compound is a compound composed of two non-metal elements.
Other examples of binary molecular compounds include nitrogen trifluoride, dihydrogen monosulfide and sulfur hexafluoride. The atoms in these compounds combine using covalent bonds, whereas compounds with salts contain ionic bonds. Binary molecular compounds are named by giving the second element the suffix "-ide." Numerical prefixes for each element indicate the number of atoms present. For example, P406 uses the prefixes "tetra-" and "hex-" to indicate four atoms of potassium and six atoms of oxygen in tetraphosphorus hexoxide.