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  • Writer's pictureJace Shoemaker-Galloway

National Mole Day: Celebrating chemistry


Have you heard the news? A special day of the year is here and Americans are ready to celebrate! Oct. 23 is National Mole Day in the U.S.A!

While National Mole Day could celebrate the little critters we call moles or those brown and/or black spots that appear on our skin, the occasion actually celebrates a basic measuring unit in chemistry known as Avogadro’s Number (6.02 x 10 23) . This annual “holiday” is observed every year on Oct. 23 for 12 hours. Because 6.02 is part of the Number, the “holiday” takes place from 6:02 a.m. to 6:02 p.m. and because the multiplier is 10 to the 23, the 23 day in the tenth month of the year was selected.

What is a mole? The unit, discovered by Amedeo Avogadro, equals the number of molecules in one mole and was named Avogadro’s number or constant in honor of his contributions to molecular theory. Born in 1776 to a family of lawyers, Avogadro graduated with a law degree but it was science that interested him and he would eventually teach science. While not much is known about his personal life, he had six children and was born and died in Turin, Italy.

Chemistry teacher, Maurice Oehler, came up with the National Mole Day idea back in the 80s. The event continued to grow year-after-year and Oehler founded the National Mole Day Foundation in 1991, a non-profit organization that helps promote chemistry education and awareness. Each year, schools across the nation participate in National Mole Day with various chemistry-related activities, which happens to coincide with National Chemistry Week.

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