What you need:
- Baking soda.
- Tray/catch plate.
- Food coloring (optional)
- Pour ½ cup of baking soda into a bowl.
- Pour a tablespoon of water into the bowl and mix together. If you want colorful rocks, add food coloring to the water at this step.
- The mixture should be thick, close to the consistency of cookie dough.
- Add more water or baking soda as needed.
- Create small round chunks of the soft baking soda mixture to form the rocks and set them out on a plate to dry.
- Pour ½ cup of vinegar into a small cup.
- After the baking soda rock is dry, set the cup of vinegar on the tray/catch plate.
- Drop the dried baking soda rock into the vinegar and watch the magic of chemistry!
Ways to expand this activity:
- Add color to the experiment. Use food coloring to dye the baking soda rock one color and the vinegar another color. Predict what will happen when they mix, then test it!
- Hide a small plastic toy in the baking soda rock. While making the baking soda rocks, include a small toy in the mixture and let dry with the toy hidden inside. Then, when you drop the baking soda rock into the vinegar liquid the toy will magically appear.
What kids learn:
- Experimentation! When kids experiment, they're learning how to learn. Failure is an important part of experimenting, so let kids try things that won’t work. It’s how they figure things out!
- Sensory play! Sensory play that lets children touch, squeeze, smell and feel helps build connections in the brain.
- Chemical reactions in action teach cause and effect.
- Measuring ingredients helps children learn about volume, get familiar with numbers and encourages comparisons between small and large amounts, all important skills in learning math.