Although we may not be aware of it, nuclear reactions affect our lives every day. Nuclear fission takes place in nuclear power plants, providing around 20% of the energy we use in the United States (and up to 72% in France). More importantly, the fusion of hydrogen into helium inside the Sun provides the source of the Sun’s light and heat, without which life on Earth would not be possible. Physicists and engineers are working on ways to harness the enormous energy of fusion for energy on Earth.
The brand-new Nuclear Reactions Gizmo allows students to analyze the steps of two common fusion pathways (proton-proton chain and CNO cycle) and several possible ways that uranium-235 can be split in fission reactions. After observing each step, students determine the balanced nuclear equation and tally the energy emitted in that step. At the end of the lesson, students can compare the energy produced in fission and fusion, both in terms of raw energy and in energy produced per mass of fuel.