Mole Day is an unofficial holiday celebrated among chemists, chemistry students and chemistry enthusiasts on October 23, between 06:02 and 18:02 (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 number, which is approximately 6.02×10²³, defining the number of particles (atoms or molecules) in one mole (mol) of substance, one of the seven base SI units. Schools around the world celebrate Mole Day with various activities related to chemistry and/or moles. 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 Amedeo Avogadro (1776-1858) and he received credit for this after his death. 

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Mole Day

Mol (eenheid)