Will a compound ending in ide contain two or three elements?

Answer 1

Molecular names ending in "ide" designate binary compounds. See below for bromides and the general class of halides. For more information on these specific compounds look in wikipedia for bromide and halide.

Compounds with bromine in formal oxidation state −1 are called bromides, and each individual chemical in this class can be called a bromide, as well. The class name can include ionic compounds such as caesium bromide or covalent compounds such as sulfur dibromide.

In general, a halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. Many salts are halides. All Group 1 metals form halides with the halogens and they are white solids.

A halide ion is a halogen atom bearing a negative charge. The halide anions are fluoride (F−), chloride (Cl−), bromide (Br−), iodide (I−) and astatide (At−). Such ions are present in all ionic halide salts.

The IUPAC (International Union of Pure and Applied Chemistry) naming rules provide for endings "ide", "ite", "ate" et cetera.

Much more information can be found by searching YA using the search string: "ide" and "ate". This question has come up many times from chemistry students