The classroom lights dim. A spotlight shines on a lone guitar player, his hair an explosion of brown frizz, his face covered in stubble. He cranks up the amplifier, distortion filling the classroom with a static buzz. He pushes his glasses up his nose, flips his plectrum around his fingers, and then pounds out a driving blues riff, singing: “It’s Mole Day!” Duh-nuh-nuh-nuh-nuh. “Six point oh two times ten to the twenty-third molecules!” Duh-nuh-nuh-nuh-nuh. The class cheers. This is the most fun they have had in chemistry class all year. It is indeed Mole Day, October 23rd, a chemistry holiday full of humor, geek appeal, and a new twist on what might otherwise be a boring high school science class.
So, what exactly is Mole Day? According to the National Mole Day Foundation, the holiday was first proposed in an article in The Science Teacher journal early in the 1980s. The idea was to create excitement in the chemistry classroom by recognizing Avogadro’s Number, 6.02×10^23, commemorating it on October 23rd of each year, traditionally between 6:02 a.m. and 6:02 p.m. After nearly a decade of increasing popularity for the event, the National Mole Day Foundation was created on May 15, 1991, which provides Mole Day resources for chemistry teachers everywhere.
Avogadro’s Number is the number of molecules or atoms in a “mole.” A mole is a unit of measure in chemistry, which represents an amount of a chemical compound or element, and is used to calculate chemical reactions. One mole of a compound or element is equal to the molecular or atomic mass of the compound or element, in grams. So, for example, water, which is defined by the chemical compound H2O, has a molecular mass of approximately eighteen (one for each hydrogen atom plus sixteen for the oxygen atom.) A mole of water, therefore, weighs eighteen grams.
Amadeo Avogadro discovered the conversion factor for calculating the number of molecules (of a compound) or atoms (of an element) that are in a mole. The number is 6.02 x 10^23. For the example above, this means that there are 6.02 x 10^23 water molecules in eighteen grams of water.
Chemistry teachers throughout the United States and even around the world celebrate Mole Day by decorating their classrooms with stuffed moles, handing out fun puzzles and activities, telling jokes, leading the class in a pledge of allegiance to the mole, and inviting students to present their own interpretations of Mole Day. Enter David, the guitar player with the original blues parody, a student who now has one more reason to love his chemistry class.