zlacker

>>qqqqqu+(OP)
Avogadro constant - I can accept the number, if someone can show me how, over a hundred years ago, without having every really seen a molecule, this number could be derived. Obviously no one ever sat there and counted them but I find it hard to believe, they could have decided this without being able to see it.

>>sloake+uy
Here's how to estimate the size of an oil molecule just using water and an oil drop: https://spark.iop.org/estimating-size-molecule-using-oil-fil...

(They use some other stuff, but you get the idea)

You can back out Avogadro constant starting with this experiment.