Density Of Penny Between 1980 And 1980

Based on the class data, the density of the penny changed dramatically between 1980 and 1985. From 1975 to 1980, the penny became 1.40g/mL less dense and from 1980 to 1985, the density dropped by 0.626. With this data and the percent composition equation we were able to determine that the second metal in the penny is Zinc with a density of 7.14g/mL. Using scholarly online sources, I was able to confirm this data concerning the second metal to be correct.
The United States Mint’s website states that in 1962, the cent’s tin content was removed making the composition of the cent 95% copper and 5% zinc. In 1982, the composition was changed to 97.5% zinc and 2.5% copper (United States Mint). The U.S. Department of Treasury stated that “the manufacturing advantages to be gained with the alloy stabilized at 95 percent copper and 5 percent zinc would be of much benefit. Congressional authority for this modification is contained in an Act of Congress approved on September 5, 1962. In 1982, the
One error in our data was that the measurements we gathered for one of our sets were rather high. Even after re-doing the entire procedure for the set, our measurements were still off. Looking back, we didn’t dry off the graduated cylinder each time before re-filling it with water, which could have thrown off our volumes and therefore our densities. Since we combined all of our data as a class, we were able compensate for these errors. One method that could be improved to ensure more accurate and precise data is to have everyone use the same balance to get the masses of the pennies. Completing more trials for each set of pennies would result in more accurate densities. We also could have had smaller year gaps for penny sets. For example we had pennies with 4 year gaps, (1985-1989, 2000-2004, etc.) but using pennies with only two year gaps (1985-1987, 2000-2002, etc.) could result in finding the exact year the density of the penny