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Does anyone know what metal this is? (right click -> "Open image in new tab" for larger image)

It has to be one of the following: magnesium, aluminum, zinc, tin, antimony, lead.

This metal was found in a laboratory where the students were performing a calorimetry experiment to determine specific heats of a few metals. I don't think it is lead (because of the color and that it is too toxic for students to use) and I don't think it is antimony (because that may be too expensive, but I could be wrong).

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    $\begingroup$ I'd say there's a fair chance that the students were doing calorimetry experiments for the oxidation of magnesium. However, it doesn't quite look like "typical" magnesium shavings and doesn't appear to have much of the gray oxide coating that you would expect after a while. How was it stored, and for how long? $\endgroup$ – airhuff Mar 2 '17 at 21:41
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    $\begingroup$ Looks like tin to me. $\endgroup$ – Ivan Neretin Mar 2 '17 at 21:45
  • $\begingroup$ Metallic lead is not that toxic. $\endgroup$ – Zhe Mar 2 '17 at 22:30
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I would guess that it is tin. The coloration and cut look right compared to an image of tin turnings (eBay listing for tin metal turnings). I'm more used to seeing aluminum and magnesium as strips rather than turnings.

Beyond that, I think it will probably take more than just the image to positively identify the metal. You could test the material with something akin to part 3 of this experiment (Linus Chem Department .pdf file).

Alternatively, you could also rerun the calorimetry experiment on the metal and see if the specific heat is consistent with any of these.

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It is probably tin judging from its appearance. The other metals are unlikely because:

  • zinc, aluminium, magnesium will have an oxide layer (no shine) unless stored without exposure to air.
  • antimony is very unlikely for calorimetry.
  • although lead is toxic, many schools still continue to use compounds of lead, like lead acetate and lead nitrate, for salt analysis (being a common use). So using lead is not unusual.
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It HAS to be one of the following: Magnesium, Aluminum, Zinc, Tin, Antimony, Lead

If you have narrowed it down to that group it should be trivial to narrow it down even further. I assume you didn't take high school chemistry.

Lead is both very heavy and very soft. Is the pile of shavings unusually heavy? Pick up a larger piece with pliers. Squeeze. if it deforms easily, it's lead. Lead also melts at very low temperatures. Heat a piece with a gas torch. If it's heavy, soft and melts almost immediately, it's lead.

Both magnesium and aluminum are very light. Is the pile of shavings unusually light? Pick up a piece, put it on a metal pan and heat it with a gas torch. If it ignites and burns with an intense, blue-white flame, it's magnesium (aluminum is much harder to ignite).

Zinc, tin and antimony are a bit harder to separate, so do the easy ones first.

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    $\begingroup$ -1 for the snark. $\endgroup$ – Icyfire Mar 3 '17 at 3:50
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    $\begingroup$ Tin is just about as pliable as lead, and melts even easier. True, it feels somewhat less heavy, but I wouldn't rely on that feeling alone to tell them apart. $\endgroup$ – Ivan Neretin Mar 3 '17 at 6:26
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    $\begingroup$ If only everyone was as smart as you Peter... $\endgroup$ – Nova Mar 5 '17 at 22:13

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