The 1982 penny has two different compositions: early in the year, it was made of 95% copper and 5% zinc, weighing 3.1 grams, while later in the year, it switched to a zinc core with a thin copper plating, consisting of 97.5% zinc and 2.5% copper, weighing 2.5 grams. This change was due to rising copper prices. If you have a good scale, you can tell if you have a copper or a zinc penny.