What defines an ionic compound?

An ionic compound is specifically defined by the presence of a metal cation and a nonmetal anion. This type of compound forms when electrons are transferred from the metal to the nonmetal, resulting in positive and negative ions that are held together by strong electrostatic forces of attraction, commonly referred to as ionic bonds.

In the case of ionic compounds, the metal typically loses one or more electrons to become a positively charged ion (cation), while the nonmetal gains those electrons to become a negatively charged ion (anion). This electron transfer is a fundamental aspect of ionic bonding and distinguishes ionic compounds from other types of compounds.

Other options do not accurately describe ionic compounds. A combination of two nonmetals generally leads to covalent compounds, where electrons are shared rather than transferred. A single element with a charge describes an ion, not a compound, which by definition requires multiple elements. Lastly, a compound formed from covalent bonds consists of atoms bonded by shared electrons, which again does not involve the electron transfer characteristic of ionic compounds.