Mole Day is an unofficial holiday celebrated among chemists in North America on October 23, between 6:02 AM and 6:02 PM, making the date 6:02 10/23 in the American style of writing dates. The time and date are derived from the Avogadro constant, which is approximately 6.02×10²³, defining the number of particles (atoms or molecules) in a mole.

The concept of a Mole was presented by Amedeo Carlo Avogadro ( 9 August 1776 – 9 July 1856), an Italian scientist considered the father of molecular theory. The best site I could find for mole activities was The American Chemical Society.

“What do you call a tooth in a glass of water?… A one molar solution.