Which condition did you change?
Labs / Chemistry
Radioactive Decay
Every dot is an unstable nucleus, and each moment it has a fixed chance to decay — no memory, no schedule, just luck. Watch the sample thin out and the curve on the right trace the same exponential shape every time, or drag across the grid to knock a few loose yourself.
Labs / Chemistry / Radioactive Decay
Radioactive Decay
Every dot is an unstable nucleus, and each moment it has a fixed chance to decay — no memory, no schedule, just luck. Watch the sample thin out and the curve on the right trace the same exponential shape every time, or drag across the grid to knock a few loose yourself.
Why it matters
Why explore this?
Chemistry connects events too small to see with changes we can measure. This model helps you link particles, energy, and conditions to an observable result.
Explore
Try the model
Remaining 100.0%Half-lives 0.00Nuclei 280 / 280
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- If each nucleus decays purely at random, why does the whole sample follow such a smooth, predictable curve?
- After one half-life, about half are gone. So why doesn't the sample vanish completely after two half-lives?
- Drag the half-life slider longer. Does the shape of the curve change, or just how fast you travel along it?
- How close does the jagged measured curve hug the ideal smooth one — and what happens to that agreement near the very end, when only a few nuclei remain?
- Knock out a big patch of nuclei by hand, then hit Reset. Does a “head start” change the half-life, or only the starting count?
Explain
Make sense of what happened
Describe what happened at the particle or energy level, then connect it to the result you saw. A strong explanation names both the cause and the evidence.
Check
Before you leave
What happened to the particles or energy?
What observation supports your explanation?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.