Ever wonder just how fast electrons are buzzing around in the orbits of atoms? There are a lot of variables that come into play, but if we keep it as simple as possible and look at a hydrogen atom, its single orbital electron is zooming in an orbital speed of 2,200 kilometers per second (7,920,000 kph/4,921,260 mph).

To put it in perspective, if the orbital distance were equal to the circumference of the earth at the equator (25,000), it would take 18 seconds for the electron to make one trip around.

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