Fizzy cup volcano

From the house

• Baking soda
• Vinegar
• A cup inside a baking dish
• Food coloring or a squirt of dish soap (optional)

How to play

1. Put 2 spoons of baking soda in the cup, plus a drop of coloring if you have it.
2. Pour a little vinegar into a small cup for them.
3. They pour. Fizz! Listen to it and watch it bubble up.
4. Add more baking soda and go again.

Fit it to your child

• Easier: Hold the cup with them and pour together, a little at a time.
• Harder: They guess which kitchen liquids will fizz, then test water, lemon juice and orange juice: only the sour ones do.

Words to use

• fizz
• bubbles
• gas
• pour
• more

Why it helps

Baking soda and vinegar react to make a gas called carbon dioxide, and seeing two ordinary things turn into bubbles is their first taste of chemistry.