Pennies made after 1982 are made with a zinc core coated in copper to give it the brown color
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The solution on the hot plate was a mixture of Zinc powder (Zn2+) and Potassium hydroxide (K+ and OH-)
As the atoms heated up, they began to move around more frequently.
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The penny was removed from the liquid. The zinc reacted with the copper causing it to stick to the sides of the penny. This created a silver penny.
The zinc atoms in the center of the penny moved towards the outside. This movement changed the center from a zinc core into a copper core.
When the metal was heated up, the zinc and copper atoms mixed together. Together, they formed an alloy. Despite its shiny gold color, this metal is actually brass.