Radioactive Decay

Alpha, beta, gamma

An interactive lesson with 7 steps, about 6 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Alpha (a helium nucleus): stopped by paper. Beta (an electron): stopped by aluminium. Gamma: reduced by lead.
• Alpha decay: A − 4, Z − 2. Beta⁻ decay: Z + 1.
• Nuclear equations must balance in both A and Z.

Steps

1. Stopping radiation
2. Three kinds of decay
3. Alpha decay of uranium
4. Beta decay of carbon-14
5. From uranium to lead
6. Sorting radiation
7. Inside vs. outside