Wondering if we are allowed to conduct a scratch test for metals?
Does anyone know what liquids they will provide when testing the density of plastics?
The metals are usually given in vials in grains or very small beads, so I don't think you can conduct a scratch test. In my experience I've never had to do one, nor was able to.
As for the liquids, it usually varies between each proctor. But usually they'll stick to the common liquids: water, NaCl (Varying concentrations), 46% isopropyl alcohol, and vegetable oils.
It's always good to expand, but I don't think you'll need anything other than those I stated. You can distinguish all of the plastics with just those 4.