Mole Day traces its origins to an article that appeared in The Science Teacher magazine in the early 1980s about a high school chemistry teacher’s reasons for celebrating the day. The idea for Mole Day took root and led to the formation of the National Mole Day Foundation, which was formed on May 15, 1991.
A mole is the quantity of anything with the same number of atoms found in 12.000 grams of carbon-12, expressed as 6.02 x 1023, popularly known as Avogadro’s constant.
The American Chemical Society plans National Chemistry Week so that Mole Day falls within the week. Today Mole Day is celebrated around the world on October 23 from 6:02 am to 6:02 pm. This year, it was observed under the theme “Moley Potter.”
Mole Day commemorates Avogadro’s number (6.02 x 1023), which is a basic measuring unit in chemistry. Mole Day was created as a way to foster interest in chemistry. Schools throughout the United States and around the world celebrate Mole Day with various activities related to chemistry and/or moles. For a given molecule, one mole is the mass (in grams) whose number is equal to the molar mass of the molecule. 
For example, the water molecule has a 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 firvst discovered by Amedeo Avogadro (1776-1856) and he received credit for this after his death.
Avogadro, whose full name was Lorenzo Romano Amedeo Carlo Bernadette Avogadro di Quaregna e Cerreto, Count of Quaregna and Cerreto, was an Italian mathematical physicist. Avogadro did a lot of work on molecular theory. One theory eventually was dubbed Avogadro’s principle. It states that if exposed to the same temperature and pressure, equal volumes of all gases contain the same number of molecules.
After his death, the principle was used by others to develop what was named Avogadro’s number. It was the French physicist, Jean Perrin, in 1909, who determined the constant using several methods. He proposed that the constant be named in honour of Avogadro.
Every year, the University of Guyana’s Chemistry Club hosts a series of activities to commemorate the day. The club was founded in 2014. It consists of an executive body: the president, vice president, treasurer, secretary and two representatives from each year and the other members. It was formed with specific objectives, which include providing opportunities for sharing and promoting interest in the chemical sciences as well as providing students with opportunities to develop communication skills.
This year, for Mole Day, the Chemistry Club organised a series of activities which included a lecture on the importance of chemists. Additionally, they had a t-shirt competition, which the second-year students won. (Photos by David McLean) (Times Sunday Magazine)
