If we can’t measure singular electrons then how can we measure these
In: Physics
To answer a slightly different question, the charge on an election was determined without needing to measure a single electron.
The most famous experiment to do this was [Millikan & Fletcher’s oil drop experiment](https://en.wikipedia.org/wiki/Oil_drop_experiment), published in 1911, and which won Millikan the 1923 Nobel Prize.
In that they got small drops of oil and moved them in an electric field to work out the charge of the oil droplet.
They repeated this for lots and lots of droplets, and found the largest number they could which divided into them. For example, if they had got 15, 27, 39, 51 as their values, they would conclude that the smallest charge was a 3 (or a factor of 3).
By doing the experiment enough times, getting enough numbers, they were fairly confident that their result; 1.5924(17)×10^(-19)C – was the smallest unit of charge possible in an oil drop.
Unfortunately some of their input data wasn’t quite right, and there were problems with them ignoring data to get a more precise result. Their result wasn’t right. But it was still far closer than anyone else had got. The current best answer is 1.602176634×10^(−19) C, although that is kind of cheating as that is used to define 1C, rather than measure the charge on an electron.
No experiment has ever found evidence to suggest smaller charges (on their own).
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