🌍 Adventure 9 — Exponential Decay & the Age of the Earth
Using U‑235, half‑life, and a DiVA chart to estimate Earth’s age — and meet Clair Patterson.
🎯 What you will learn
- Radioactive decay follows an exponential law.
- Half‑life acts like a built‑in clock (powers of 2).
- v(t) is the decay speed (how fast uranium turns into lead).
- Area under v(t) tells how much mass has changed.
🎥 Watch: Why exponential growth and decay are special
📖 1) Read / Listen: Story
Watch exponential change reveal patterns that stretch from tiny scales to billions of years.
✏️ 2) Do the Adventure Activity
Use the DiVA chart to estimate Earth’s age from uranium decay — and see how it matches Clair’s discovery.