"Chemists need stoichiometry to make the scale of chemistry more understandable - Hank is here to explain why, and to teach us how to use it."

Just how small are atoms? And what's inside them? The answers turn out to be astounding, even for those who think they know. This fast-paced animation uses spectacular metaphors (imagine a blueberry the size of a football stadium!) to give a visceral sense of the building blocks that make our world. View the complete lesson at TED-Ed.

The word "mole" suggests a small, furry burrowing animal to many. But in this lesson, we look at the concept of the mole in chemistry. Learn the incredible magnitude of the mole--and how something so big can help us calculate the tiniest particles in the world. View the complete lesson at TED-Ed.