The approximate time since the organism died can be worked out by measuring the amount of carbon-14 left in its remains compared to the amount in living organisms.This lesson is the third in a three-part series about the nucleus, isotopes, and radioactive decay.Atoms may stick together in well-defined molecules or they could be packed together in large arrays.For students, understanding the general architecture of the atom and the roles played by the main constituents of the atom in determining the properties of materials now becomes relevant.Empty the graduated cylinders between classes if the volume is more than about 25 ml.
The results showed that Ötzi died over 5000 years ago, sometime between 33 BC. It is found in the air in carbon dioxide molecules.By measuring how much carbon is left in a sample as well as its radioactivity, we can calculate when the organism died. In this activity, you will work backwards to solve a puzzle, much like scientists work backwards to find the time that an organism died." Procedure Give each student a copy of The Case of the Melting Ice student sheet.You may group them in any size group, but working in pairs is optimal for this exercise.On a separate sheet of paper, immediately record the volume of Frosty's melted remains (water) in your graduated cylinder and note the time on the clock.Make a data table and, at regular intervals (you decide how long), record the time on the clock and the volume of water in the graduated cylinder.