Besides smelling, touching and looking at the physical appearance of a substance, there are other ways to know for sure what that substance is. This is where chemical properties come in. A chemical property is a property of a substance that is observed when a substance undergoes a chemical change. The chemical change is a type of change that also changes the identity of a substance due to breakage and formation of new chemical bonds, as shown in the figure below: The figure shows a chemical change where two substances, A and B, form and break bonds with each other and other substances, C and D.
As of 2014, dimes have the smallest diameter of any U.S. coin and are also the thinnest. A penny is 1.52 mm thick with a diameter of 19.05 millimeters. It weighs 2.5 grams and has plain edges. A nickel is 1.95 millimeters thick with a diameter of 21.21 millimeters. It weighs 5 grams and has plain edges. A quarter is 1.75 millimeters thick and has a diameter of 24.26 millimeters.
The Mint's greatest concern was in finding an alloy which would use no nickel, but still satisfy counterfeit detectors in vending machines. An alloy of 56% copper, 35% silver and 9% manganese proved suitable, and this alloy began to be coined into nickels from October 1942. In the hopes of making them easy to sort out and withdraw after the war, the Mint struck all war nickels with a large mint mark appearing above Monticello.