Population tables. of world cities. This article lists the most populous cities in the world defined according to a concept of city proper. A city proper is a locality defined according to legal or political boundaries and an administratively recognised urban status that is usually characterised by some form of local government. Cities proper and their boundaries and population data may not include suburbs. World Urbanization Prospects, a UN publication, defines population of a city proper as the population living within the admi
The mass of one cubic centimeter of copper is 8.96 grams, while the mass of the same amount of zinc is 7.13 grams. 1  A penny is made of copper and zinc. 2  Copper is heavier than zinc. 3  The cost of copper has been on the rise during the past couple of decades.
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.). Back in the early 1970s, the rising price of copper was pushing the cost to make a penny over its face value of one cent. Fortunately, the price of copper dropped and production continued.