Asingle-element cation and a single-element anion create what type of ionic compound

            Binary Ionic Compound is formed when a single-element cation and a single-element anion combine.

Explanation:
                   Binary compounds are those compounds which are made up of only two elements. When metal looses single electron it is changed to Cation and a non-metal on accepting one electron creates an Anion. Thus a Binary Ionic compound is formed by the cation and anion.

Example:
                Sodium Chloride, NaCl: Made up of Na⁺ and Cl⁻

                Potassium Iodide, KI: Made up of K⁺ and I⁻

                Lithium Bromide, LiBr: Made up of Li⁺ and Br⁻

The total number of electrons is 14