What is Mole Day?

Mole Day is an unofficial holiday that commemorates a chemical principle known as the Avogadro constant or Avogadro's number; this day falls on October 23 and is marked at 6:02 a.m. or 6:02 p.m. This is because Avogadro's number is 6.02 x 10^23. This number represents a unit of measurement called a mole.

Because October is the 10th month, its 23rd day is one option for celebrating Mole Day. Other options include the second day of June (6/02 in month/day format) and the sixth day of February (6/02 in day/month format). Mole day can be celebrated with chemistry-related activities and research.