"Keep in mind that atoms are extremely small. One hydrogen atom, for example, is approximately 5 x 10-8 mm in diameter. To put that in perspective, this dash - is approximately 1 mm in length, therefore it would take almost 20 million hydrogen atoms to make a line as long as the dash. In the sub-atomic world, things often behave a bit strangely. First of all, the electron actually spins very far from the nucleus. If we were to draw the hydrogen atom above to scale, so that the proton were the size depicted above, the electron would actually be spinning approximately 0.5 km (or about a quarter of a mile) away from the nucleus. In other words, if the proton was the size depicted above, the whole atom would be about the size of Giants Stadium."