Happy Mole Day!

less than 1m read

·Nov 11, 2024

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?

Surf Sisters - Ep. 2 | National Geographic Presents: IMPACT With Gal Gadot

We lost $1,000,000+ (Here’s What We Learned)

View All

The Beauty of What We Just Don't Know (A Philosophy of Trust)

There’s this human tendency to find explanations for the things that we don’t understand. This tendency has been the birthplace of folklore and creation stories that are cornerstones of many religions. Imagine living in the tribal age, gazing at the stars…

2015 AP Physics I free response 2 a and b

Some students want to know what gets used up in an incandescent light bulb when it is in series with a resistor: current, energy, or both. They come up with the following two questions: in one second, do fewer electrons leave the bulb than enter the bulb?…

Introduction to photoelectron spectroscopy | AP Chemistry | Khan Academy

In this video, we’re going to introduce ourselves to the idea of photoelectron spectroscopy. It’s a way of analyzing the electron configuration of a sample of a certain type of atom. So what you’ll often see, and you might see something like this on an ex…

How Many Photos Have Been Taken?