Molecular Compounds: Formulas and Nomenclature

Molecular compounds are formed by atoms of two or more nonmetallic elements via covalent bonds. However, the same elements may combine in different ratios, giving rise to different molecular compounds. Hence, each molecular compound is described using distinct chemical formulas and systematic naming based on the number of atoms of its constituent elements.

A binary molecular compound is represented by first indicating the more metal-like element situated to the left and bottom of the periodic table. The more nonmetallic element is denoted subsequently. Numerical subscripts signify the number of atoms of each element.

These binary molecular compounds are named using a format beginning with a Greek-prefix indicating the number of atoms of the first element, followed by the element name. The prefix 'mono-' is usually omitted for the first element. 

A second Greek-prefix denotes the number of atoms of the second element, which is followed by the element base-name ending with the suffix ‘-ide'. Hence the two different molecular compounds of carbon and oxygen, CO₂ and C₂O, are named carbon dioxide and dicarbon monoxide, respectively.

Acids, which are hydrogen-containing molecular compoun