- Clear plastic drinking straw, preferably a 0.2 inch diameter straw.
- Metric ruler
- Fine-tipped permanent marker
- Clean narrow-necked, small bottle with lid. Travel size bottles like these available from Amazon work well. Washed empty food coloring or vanilla extract bottles work well too.
- Rubbing alcohol
- A few drops or red, blue, or green food coloring. Liquid food coloring works best.
- Paper or cloth towels
- Modeling clay. Air-dry clay works well. Ultra-light modeling clay is easy to model and clean.
- Medicine dropper or syringe
- Water
- Small bowl
- Ice cubes
- Optional: Store-bought thermometer
