In chemistry, the amount of substance in a given sample of matter is defined as the number of discrete atomic-scale particles in it divided by the Avogadro constant "N"A. In a truly atomistic view, the amount of substance is simply the number of particles that constitute the substance. The particles or entities may be molecules, atoms, ions, electrons, or other, depending on the context. The value of the Avogadro constant "N"A has been defined as . In the truly atomistic view, 1 mol = particles (the Avogadro number) and therefore the conversion constant is simply "N"A = 1. The amount of substance is sometimes referred to as the chemical amount.