A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a of the substance.

A unit of substance that contains the Avogadro number of atoms or molecules is referred to as a mole of the substance.

Explanation:

The mole (symbol: mol) is the unit of measurement for amount of substance in the International System of Units (SI). A mole of a substance or a mole of particles is defined as exactly 6.02214076×1023 particles, which may be atoms, molecules, ions, or electrons. In short, for particles, 1 mol = 6.02214076×1023.