I was asked recently to write a short essay on environmentalism to be published in a book on âKey Concepts in Critical Management Studiesâ to be published by Sage later in 2010. I hope itâs useful for those who want a little bit of history and critical understanding of environmentalist as a concept and a movement.
Hand sorting the 1982 Copper from the Zinc pennies. 1982 was the transition year for the US Mint to stop making pennies from copper and switch to zinc. There... Hand sorting the 1982 Copper from the Zinc pennies. 1982 was the transition year for the US Mint to stop making pennies from copper and switch to zinc. There are sorting machines that can be purchased to do this work, but if you dont have a machine, your ears can do the job!
If your Lincoln Memorial penny has a date before 1982, it is made of 95% copper. If the date is 1983 or later, it is made of 97.5% zinc and plated with a thin copper coating. For pennies dated 1982, when both copper and zinc cents were made, the safest and best way to determine their composition is to weigh them. Solid copper pennies weigh 3.11 grams (+/- 0.130 g.), whereas the copper plated zinc pennies weigh only 2.5 grams (+/- 0.100 g.).