This week the students tackled isotopes. We began with a review of the atomic number, protons, neutrons, electrons, and electron shells. After that refresher, the students worked through an isotope worksheet in their textbook. The main point of the worksheet was for the students to realize that the number of protons in an element never changes. Rather, it is the number of neutrons that varies. They filled out a table and constructed the nucleus of each atom using toothpicks and styrofoam balls. Some students were able to grasp this concept, but most were confused. I think a two-prong approach might improve their isotope understanding. First, the worksheet only had the students calculate 2 isotopes per element, and I don’t think that really emphasized the point for them. They were able to figure out that no two isotopes were the same, but they weren’t quite sure why. Second, their textbook explained that the nucleus of each isotope varies, but it didn’t give them any information on why this matters. It would be a lot to squeeze into one lesson, but I think the lesson might be more memorable if it took place over two days and covered both how the nuclei of the isotopes vary and how we use isotopes in every day life. On the other hand, if the main goal of the curriculum is to make sure the students know something about protons, neutrons, and electrons, then a two lesson on isotopes is probably overkill.