22-23 October 15

Tomorrow, 10-23, marks the annual celebration of Mole Day, by chemists and their friends worldwide. The number 6.022 X 10**23 counts the number of things (atoms, molecules, paper clips, pianos, whatever) in "one mole" of them. In plain English that number is 602.3 sextillion. The mole is the simplest way to compare amounts of reacting substances. One mole of carbon atoms (C), weighing 12 grams, reacts with one mole of oxygen molecules (O₂), weighing 32 grams, to create one mole of carbon dioxide (CO₂), weighing 44 grams. In the photo I am holding 1 mole (342 grams) of sucrose (C₁₂H₂₂O₁₁) and one mole (18 grams) of water (H₂0); I added a few hundred quadrillion molecules of blue food coloring (in one "tiny drop") to the water for visibility.