In chemistry, a mole is a unit of measurement. It is the quantity of anything that contains the same number of particles that can be found in 12 grams of carbon-12. A mole of anything is 6.02x1023 atoms of that thing. For example, a mole of oxygen is 6.02x1023 of oxygen atoms. This number, 6.02x1023 is considered to be Avogradro’s number, named after the Italian scientist Amedeo Avogradro.