23rd October: Happy Mole Day

Mole Day recognizes a special number in chemistry. We’ll eliminate any visions of a burrowing creature celebration immediately. Chemists and chemistry students mark the occasion each year on October 23rd. More specifically, the celebrations take place between 6:02 AM and 6:02 PM. In the U.S., the time and date are written 6:02 10/23. The time and date are derived from Avogadro’s number. Avagadro’s number is approximately 6.02×10^23. Hence, defining the number of particles (atoms or molecules) in one mole of substance, one of the seven base SI units. A mole is a unit of measurement used in chemistry to express amounts of a chemical substance. The Avogadro constant is named after the early 19th-century Italian scientist Amedeo Avogadro. Learn more about molecular science and Avogadro’s number. Explore the international system of measurement using moles.