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It's a metal, but there seems to be some kind of idea going around that it's a base metal that's rather dull, whereas on encountering some zinc it seems a surprisingly shiny metal. Much heavier than aluminium, it appears the density (specific gravity) is 7.1 , and the melting point is surprisingly low at 419 degrees C.
Zinc is usually seen, not in the pure solid form, but as a thin layer of plating on galvanised steel. Corrugated steel roofing galvanised with zinc is more durable than the iron alone which would rust very quickly. Curiously, such corrugated iron panels on roofs in Belize have acquired the slang term "Zink".
Solid zinc is found as shiny metal cases inside transmitters, usually housing some closed cavity items, critical components, etc. With there being a mystery about the identity of the metal involved, the density scales were used. Well, it might have been silver!
Zinc is sometimes used in its pure form as sacrificial anodes. Based on electrochemical science, not superstition, the idea is that you don't want your propeller to corrode away, so you attach a sacrificial anode made of zinc. See various contacts in boating. The point about this is that it's the most anodelike metal that is going to dissolve, so as zinc is much more anodelike than the bronze of a propeller or the steel of a ship's hull, it will be the zinc which will dissolve, leaving the other items uncorroded.
The fact that zinc makes a good negative terminal is also used in batteries, for example in zinc-carbon batteries. Also, when making your own battery using a piece of copper and a piece of zinc, suspended in some conductive material such as orange juice, it is the zinc which is the negative terminal.
The fact that the more negative item will dissolve has also been notoriously used by plumbers in the old days, fitting a copper ballcock valve in a zinc water tank, knowing full well that they would be called out on a later occasion when the zinc tank finally corroded through and sprang a leak.
Zinc is a vital mineral in the diet, but it's best to have the right amount, or zinc poisoning can result. It was said that during the war, people working in ammunition factories became unusually thin because of having too much exposure to zinc. Whether this is true or not is another matter.
Some animals are even less tolerant to zinc than humans are. Dogs, for example, can be made quite ill by even small amounts of zinc, and parrots can be killed by their water being contaminated with zinc. In contrast, with humans, it is zinc deficiency which is more likely to be a problem. The problem is best avoided by taking a regular multi vitamin/mineral supplement, rather than doing anything drastic such as swallowing small coins, which can cause other problems!
Here are a few useful ZINC contacts...
http://www.nyrstar.com/ - Nyrstar - zinc mining
http://www.riotinto.com/ - Rio Tinto Zinc
www.zinc.org - International Zinc Association
And others to be added.
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