Last weekend we were looking at the steeple of a church. It was sort of a green mottled color. We found out it was made of copper. Pennies are made of copper too—why is the penny a brownish-reddish color and the church steeple is green?
When copper is exposed to oxygen in the air, there is a chemical reaction that turns it green. It takes years for the copper to turn from the coppery metallic color to the greenish-bluish color. Did you know that the Statue of Liberty is made of copper?
So why don’t pennies turn green? Well, being in people’s pockets, change purses, and in people’s hands, rather than exposed to the air like the church steeple helps. And pennies aren’t pure copper. Pennies are made from an alloy (mixture) of copper and zinc.
Copper is an element. Elements are the basic building blocks of… well, everything! Combined together, elements form chemical compounds. This video from our new favorite album “Here Comes Science” is about the periodic table, which lists all the elements: