Monday, June 2, 2008

Gold Penny Demo

In today's class, we learned about alloys. The students got a penny made prior to 1982, thoroughly cleaned it, and then placed it in a heated bath of powered zinc and sodium hydroxide. The penny turned a silver color. Then, holding the penny in long tweezers, we heated the penny in the Bunsen burner until it turned gold. It was then dunked into water to cool it off. Everyone got to take home a "Gold Penny"! Really though, it was a brass-coated penny. When put into the fire, the coating of zinc melted with a little of the copper penny, forming the alloy brass.

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