What makes electricity want to move? And when it does, is it the same electrons along the way? Or is it pushing electrons out of atoms in like a domino effect?
In: Physics
Electricity (or more properly, electric current) is not electrons, it’s the *flow* of electrons (in the same sense that a current in water is not water, it’s the *movement* of water).
Current is created by a difference in potential (a “voltage”) between two points. Simply put, electrons want to move closer to one side of the system. So the electrons closest to that side move towards it, and then the next-closest electrons move into the area they leave behind, and so on. Imagine a bunch of people lined up for something: the first person in line moves, which lets the second person in line move, and so on. To extend the water analogy, a voltage is like a difference in height: water flows downhill, electricity flows “downvoltage”.
This can’t sustain for very long by itself, because electrons want to spread out. So there’d be a very slight initial motion, but then the “downvoltage” area would be too packed. (This is what happens when you get zapped by static electricity.)
Instead, electricity in everyday objects flows in a *circuit*: some outside source of energy (like a battery) is pushing electrons along, and they move in a loop in one direction. The water analogy here is a fountain: water flows down from the top of the fountain to the bottom, but the water doesn’t run out because a pump raises it back to the top again. So yes, it is the same electrons, and they are sort of pushing one another in a domino effect.
(What I’m describing here is *direct* current – the electricity that comes out of your wall is actually *alternating* current, where the flow of electrons goes back and forth. Alternating current turns out to be more convenient for engineering purposes.)
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