How do scientists count things too small to see? With a very big number! October 23 is Mole Day, a celebration of chemistry and a number that helps scientists make sense of the tiny particles that make up our world. You already use words that represent specific quantities. A pair means two. A dozen means twelve. In chemistry, a mole means approximately 6.02 × 10²³ particles, such as atoms or molecules. That’s a 6 followed by 23 more digits! Why would anyone need such an enorm