View full lesson: http://ed.ted.com/lessons/chemical-reactions-zaidan-and-morton

When molecules collide, chemical reactions can occur -- causing major structural changes akin to getting a new arm on your face! George Zaidan and Charles Morton playfully imagine chemical systems as busy city streets, and the colliding molecules within them as your average, limb-swapping joes.

Lesson by George Zaidan and Charles Morton, animation by Neighbor.