Mole Day
October 23 · Level 5 · #1124 of 2238
Mole Day is a chemists' holiday for the mole, the unit for amount of a substance, and for Avogadro's number. The date is a pun: 10/23 echoes 6.02 × 10²³, the number of particles in one mole.
How it is celebrated: students and teachers hold chemistry quizzes, make felt moles (the animal shares its name with the unit), draw puns and run experiments. Some keep the party going from 6:02 a.m. to 6:02 p.m.
In 1811 Amedeo Avogadro proposed that equal volumes of gases at the same conditions hold equal numbers of molecules. The number that carries his name was only measured after his death.