# Pick Two Classic Experiments

Part of the Nuclear Science Merit Badge Digital Resource Guide: [Introduction & Overview](https://merit-badge.university/merit-badges/nuclear-science/guide/index.md)

*4. Classic Experiments*

> **4.** Do TWO of the following:

You must choose exactly 2 options from this requirement.

## Your Options

- **[Req 4a — Build an Electroscope](https://merit-badge.university/merit-badges/nuclear-science/guide/req4a/)**: Build a simple detector that shows how electric charge behaves and how radiation can discharge it.
- **[Req 4b — See Tracks in a Cloud Chamber](https://merit-badge.university/merit-badges/nuclear-science/guide/req4b/)**: Watch ionizing radiation leave visible trails in a supersaturated vapor.
- **[Req 4c — Model Half-Life](https://merit-badge.university/merit-badges/nuclear-science/guide/req4c/)**: Use a hands-on experiment to show how radioactive decay follows a pattern even when individual atoms decay randomly.

## How to Choose

**Choosing your two experiments** — Think about materials, time, and what you want to understand

- [ ] **Best low-cost build**: 4a usually uses simple household materials and teaches electrostatics clearly.
- [ ] **Best wow-factor demonstration**: 4b lets you see radiation tracks, but it takes more setup and careful adult help.
- [ ] **Best for graphing and math-minded Scouts**: 4c turns decay into data you can count and discuss.
- [ ] **What you will gain**: 4a builds understanding of charge and detection, 4b helps you visualize invisible particles, and 4c helps you explain probability, decay, and half-life.

> **Tip**
>
> A balanced pair is often 4b plus either 4a or 4c. That way one experiment helps you see radiation, and the other helps you measure or model it.

[Detecting and Measuring Ionizing Radiation - A Short History (PDF)](https://www.iaea.org/sites/default/files/publications/magazines/bulletin/bull23-4/23405043136.pdf): A short history showing how simple detector ideas grew into the tools used in modern nuclear science.

Start with the electroscope if you want the simplest classic detector first.

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