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, modern pennies(post 1982) are 97.5% Zinc with the remaining 2.5% being electrolytically plated copper. Up till 1982, pennies were made from and alloy composed of 95% Copper, 2-3% Zinc and 2-3% Tin. Additionally, the 1943 wartime penny or the steel penny was made of steel with zinc plating, so that copper could be saved for military use.