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.
Actually most modern U.S. coins are almost entirely copper. Nickels are 75% copper; dimes, quarters, and halves are 92% copper, and dollars are 88.5% copper (source: U.S â¦. Mint). The only coin that's NOT mostly copper is the penny. Starting in mid-1982 the coin's composition was changed to a core of 97.5% zinc with a plating of 2.5% copper.