About National Mole Day
National Mole Day recognizes a special number in chemistry. Chemists and chemistry students mark the occasion each year on October 23.
The mole is the unit of amount in chemistry. It provides a bridge between the atom and the macroscopic amounts of material that we work with in the laboratory. It allows the chemist to weigh out amounts of two substances, say iron and sulfur, such that equal numbers of atoms of iron and sulfur are obtained.