Definition of 'optimum'. Word Frequency. optimum (ÉptÉªmÉm ) or optimal. adjective. The optimum or optimal level or state of something is the best level or state that it could achieve. [formal] Aim to do some physical activity three times a week for optimum health. ...regions in which optimal conditions for farming can be created.
Quick Answer. Pennies produced by the U.S. Mint since 1982 are an alloy of 2.5 percent copper and 97.5 percent zinc. The penny weighs 2.5 grams, so each penny contains 0.0625 grams of copper.
The oldest metal object found in the Middle East consists of copper (it was a tiny awl dating back as far as 5100 B.C.). The U.S. penny was originally made of pure copper (nowadays, it is 97.5 percent zinc with a thin copper skin). Copper ranks as third-most-consumed industrial metal in the world, after iron and aluminum, according to the U.S. Geological Survey. About three-quarters of that copper goes to make electrical wires, telecommunication cables and electronics.