The tiny atoms that make up our world are made up of even tinier protons, neutrons and electrons. Though the number of protons determines an atom's identity, it's the electrons -- specifically, their exact location outside the nucleus -- that particularly perplex scientists. George Zaidan and Charles Morton show how to make an educated guess of where those itty-bitty freewheeling electrons might be. [Directed by Karrot Animation, narrated by George Zaidan].