School and Work

When I was a kid I used to like to do all kinds of weird experiments. I noticed when I ran current through salt on aluminum paper it will create a yellowish brown substance... I never got to figure out what it was...

Only serious answers from people with knowledge about chemistry please.

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15 minutes is 0.25 hours
100W is 0.1 kW.
So the bulb CONSUMES (0.25 * 0.1) kWh = 0.025 kWh

If the bulb PRODUCES 0.0015kWh of light energy, the efficiency is equal to:

energy produced divided by energy consumed = 0.0015 / 0.025 = 0.06

expressed as a percentage this is = 6% efficient (not very good efficiency !)

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They aren't really any different. Just different aspects of the same subject that we study.

"static electricity" or electrostatics is studying charge situations whereby all systems are in ELECTROSTATIC EQUILIBRIUM. That is, they aren't really actively doing any re-distribution.

"Current electricity" is what you shouldn't call it. You should just call it circuits. That is when we focus a study on an application of when electrostatic equilibrium ISN'T the case, and the results are interesting to us.
http://amasci.com/miscon/eleca.html#statcur

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