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To: babygene; stormer
“Any half competent freshman chemistry student could measure density and tell the difference between gold and tungsten.”

You think? I believe that is false...

You're most like correct, babygene. Density = mass / volume. Here are typical density values.

Gold = 19.32 g/mL
Tungsten = 19.35 g/mL

So a gold-coated tungsten bar would have a density a bit below 19.35. Perhaps it would be 19.34.

A chemist just might catch that if he had a VERY precise massing device and a VERY precise volume device. Typical high school lab devices would not catch that small a difference.

And to make it even more confusing, not all scientists will agree on those given densities! There are fluctuations due to temperature, etc. Bottom line, forget density as a test here.

14 posted on 12/07/2013 10:18:24 AM PST by Leaning Right (Why am I holding this lantern? I am looking for the next Reagan.)
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To: Leaning Right

I was actually referring to a college setting where lab scales commonly are accurate to .0001 grams. Volumetric devices used are scaled depending on the sample, so there is a wide range of options available. Typically, analysis is done under stand temperature and pressure, so your contention that there is disagreement regarding densities is void. But where did I even mention density testing as an analytical method? It certainly is a method that could be used, and although time consuming, would certainly provide a useful result. But if I wanted a quick and dirty test, I’d just heat it up - gold melts a couple of thousand degrees below tungsten.


28 posted on 12/07/2013 11:12:50 AM PST by stormer
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To: Leaning Right

Correct.

The differences are so small, they are likely to be exceeded by inherent measurement errors.

A freshman chem student ain’t gonna be able to say squat about it...


29 posted on 12/07/2013 11:13:16 AM PST by djf (Global warming is a bunch of hot air!!)
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