By the end of this year or early next year, Chemical Abstracts Service (CAS) expects to register the 70 millionth organic or inorganic substance in its CAS REGISTRY – that’s the same number as pet cats in the U.S., the oldest dinosaurs and the number of sheep in New Zealand in the early 1980s.

To celebrate the registration of the 70 millionth substance, CAS is inviting you and your readers to participate in a “Chemistry Pool” to predict the date and time the substance will be entered. We’ve developed an online prediction contest,  open to any and all, with the closest guess receiving an Apple iPad.

Good luck if you enter – and let us know if you win (or come close even!)