Half-Life Makes Sense — When Students See the Halving PatternMany students learn half-life of radioactive decay as a formula: divide by 2, divide by 2 again… done.But half-life is really about how quantities change in a predictable way over time. In this lesson, instead of giving students the rule first, students collect data, track how much remains, and identify the pattern of halving across time intervals. By analyzing how quantities decrease and using that pattern to make predictions, studen