1. anastasia_plotnikova says:

Oh, numismatists can tell by sight and touch what kind of metal they're holding. But for beginners there is a method!

It came to us from Archimedes (yes, from the 3rd century BC!) and it is called the hydrostatic weighing method. It sounds scary, but it's actually easy. The main thing is to do everything in order:

1. We take a coin (I have a copper one). We weigh it.

2. We take a cup and pour water into it, throw our coin. The coin must be covered with water.

3. We weigh a glass of water and a coin. And we reset the scale at this weight. (There is such a function in the market).

4. We take a thread, make a loop and tighten the coin. Again, we submerge it in a glass of water, but so that it does not touch the bottom and walls. We get the effect of water displacement. We look at the scales and weight.

5. Now divide the weight of the coin by the weight of water displacement. This is how the density coefficient is obtained.

6. Let's Google the special table for metals and their density coefficient and see what came out of our result. For example, 8.85 is a copper alloy.

That's it ðŸ™‚