A mole is a unit of measurement used to express the amount of a substance in chemistry. It is defined as the amount of a substance that contains the same number of particles (atoms, molecules or ions) as there are in 12 grams of pure carbon-12. This number is known as Avogadro's constant and is approximately 6.022 x 10^23 particles per mole. The mole is often abbreviated as "mol".
