They should also understand that the atoms of any element are alike but are different from atoms of other elements.
Atoms may stick together in well-defined molecules or they could be packed together in large arrays.
Advise students to read through the case first so that they understand what they should do.
Students should answer the questions on their student sheet based on their graphs and the data they collected.
Students can check their answers by going to the Radiometric Dating page by Professor Pamela Gore from the Georgia Perimeter College.
The second lesson, Radioactive Decay: A Sweet Simulation of Half-life, introduces the idea of half-life.
By the end of the 8th grade, students should know that all matter is made up of atoms, which are far too small to see directly through a microscope.