When biologists talk about moles, they’re usually referring to the tiny, grey rodents that dig underground to find tasty earthworms. When chemists talk about moles they’re usually referring to something entirely different. The term ‘mole’ represents a number in chemistry the same way the word ‘dozen’ represents 12 of something to a baker. In this case, one mole represents 6.02 x 10²³, a humongous number!