This is not a day to celebrate moles. It's a day to remember that chemists use a special number in chemistry called the mole. They do this on October 23, which is National Mole Day. Avogadro's number is a number that describes the number of particles in a mole. The number of particles in a mole is approximately 6.02 x 10^23. The number is used to calculate the molar mass of a substance. A mole is also known as a gram-molecule, defined as one gram of a substance containing the same number of molecules as atoms in 12 grams of carbon-12. In chemistry, a mole is the unit of measurement used to describe the amount of a chemical substance. The Avogadro constant is the historical name for the current Avogadro constant. It was named after the early 19th-century Italian scientist Amedeo Avogadro.  

National Mole Day is celebrated annually on October 23.

A chemistry teacher read an article in The Science Teacher in the early 1980s. He became inspired to create a day dedicated to moles. He founded the National Mole Day Foundation in 1991. This foundation and its holiday are still alive today.