Monatomic ion

A monatomic ion is an ion consisting of a single atom. If an ion contains more than one atom, even if these atoms are of the same element, it is called a polyatomic ion. For example, calcium carbonate consists of the monatomic ion Ca²⁺ and the polyatomic ion CO₃²⁻.

A type I binary ionic compound contains a metal (cation) that forms only one type of ion. A type II ionic compound contains a metal that forms more than one type of ion, i.e., ions with different charges.

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