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.
At the very least, a change in the composition of the American penny seems likely. In 1982, Congress authorized the Treasury to make such a change, and it did. Before then, pennies were 95 percent copper and 5 percent zinc, Mr. White says. Pennies manufactured since have been copper-plated zinc, with zinc making up 97.5 percent of the coin and copper only 2.5 percent. Steel, which was used in pennies in World War II, could be substituted next.