How can you tell if a substance is pure gold or not?

Question

how can you know if a substance is pure gold or just like a mixture of some other random metal with gold?

Also, what does Archimedes has to do with all this? i know he found some sort of solution to this problem...but i'm not quite sure how?

Answer 1

find its density. or take it to a synagogue.

Answer 2

you measure its density

Answer 3

Archimedes thought of the way to measure the volume of an irregular object (a crown, in his case) by water displacement.  Here is how you can do it:

Put a pitcher in the kitchen sink, and fill it until it is overflowing.  Arrange the spout so you can catch the overflow in a measuring cup.

Then insert the object you want to know the volume of, and catch the overflow.  The water overflow takes up the same space as the object you put in the water.

If you go weigh the object, then you can divide the weight in grams by the volume in cubic centimeters and compare it with gold, which has a density of 19.3 g / cc.  If the density is more than a tiny bit off, it's not pure gold.

Grandpa

Answer 4

You can tell the purity of gold by its weight and hardness,

The purer the gold, the softer and heavier it will be. The purity of gold is also measured in carats, 24 being the purest. Archimedes was a mathematician, physician, an inventor and an astronomer among other things.

Archimedes was reputed to have found a way to tell if base metal/s had been used either instead of, or blended with gold to cheapen it. If you've never heard of "Alchemy", it was supposedly the method in which base metals,ie lead, iron, copper etc was transformed into pure gold. He wasn't the only one looking for a way to do that.