The Scientific Mole T-Shirt by Nathan Mazur from the NeatoShop
October 23rd is always Mole Day, but only the hours between 6:02 AM and 6:02 PM. According to the National Mole Day Foundation, it's a calendar holiday that celebrates Avogadro's Number (6.02 x 1023), a basic measuring unit in chemistry.
For a given molecule, one mole is a mass (in grams) whose number is equal to the molar mass of the molecule. For example, the water molecule has an molar mass of 18, therefore one mole of water weighs 18 grams. Similarly, a mole of neon has a molar mass of 20 grams. In general, one mole of any substance contains Avogadro's Number of molecules or atoms of that substance. This relationship was first discovered by Amadeo Avogadro (1776-1858) and he received credit for this after his death.
Ways to celebrate include learning about Avogadro and his experiments, measuring substances in chemistry class, telling mole jokes, and eating Mexican food: an entree with mole sauce and guacamole or something else made of avogadros. Me, I'm getting one of my mole-ars crowned.
If you want to discuss your Mole Day festivities, there's a Twitter account for the holiday.
Learn more about Mole Day in our previous post, 5 Fun Facts about Mole Day.