Happy Mole Day!

Hey everybody! Rocco T. Mole here to wish you a Happy Mole Day from all of us at Khan Academy!

Yes, moles! The chemistry concept, not the critter. Now, in case you’ve been living under a rock (like me), a mole is another name for Avogadro’s number which is (approximately) 6.022 times 10 to the 23rd. Kinda like how a “dozen” is another name for 12.

So why do we need a name for such a big number?! Well, we could write it like this: 602,214,129,000,000,000,000,000 (Thank you). But that would take a while! Moles make counting easier for chemists, particularly when talking about atoms or molecules.

So for the number of molecules in a cup of water, you could write an 8 with 24 zeros after it... OR you could just call it 13 moles of water instead! (Thank you Yuki) Isn't that easier?

Now, the moral of this story is: moles are the best! And if you want to learn more about chemistry, or anything, really, head to our website: khanacademy.org.

That's Khan as in Ghenghis, no relation; and Academy, as in academy. Happy Mole Day everyone! You can learn anything!

Are we still–we're not recording, right?