After our Fizzy St. Patrick’s Day Science activity a few weeks ago, we once again had a lot of wet baking soda left over, and E and I decided to turn them into Fizzy Treasure Rocks: We took large handfuls of wet baking soda, placed a gold coin in the middle, and formed the baking soda around it.
Don’t forget to check out other Fizzy Experiments Your Kids Will Love.
Materials for Fizzy Treasure Rocks
- Wet baking soda. (If you don’t happen to have any left over from another activity, you can just add a little water to unused baking soda. Or simply do another activity first 😉 )
- Gold coins or other small treasures to hide in the baking soda.
- Fizzy tub colors, liquid watercolors or food coloring.
- Squeeze bottles.
- Water table (optional but great for minimizing messes and for sibling play).
We let the fizzy treasure rocks dry for several days. Try to avoid handling them as much as possible, as they can be quite fragile once they’re dry.
When we’d decided that they were dry enough, I gently placed the baking soda rocks in the water table. I also scattered some extra dried out baking soda that we hadn’t turned into treasure rocks all over the water table.
E wanted to color the vinegar green again and put yellow and blue fizzy tub color tabs in one squeeze bottle and one pitcher full of vinegar.
Then she got to work while N watched.
She didn’t spend that much time on the treasure rocks, though.
Instead, she decided to grab a small cup, fill it with crumpled up baking soda and add a tiny bit of vinegar. She’d wait until the fizzing stopped, add more baking soda, then add another tiny bit of vinegar. It was quite fun to watch, and she was extremely patient.
Only after she’d done that for a really long time did she decide to make the cup overflow 🙂
Meanwhile, N went for mass fizzing action when he poured out the larger container all at once.
He chose the sensory approach to this activity and spent some time putting his hands in the foam over and over and splashing around.
When E was done with the squeeze bottle, he imitated her approach – he didn’t mind that the bottle was empty at this point 😉
To finish off the activity, E asked for some more vinegar to work on the treasure rocks some more.
For some reason, neither child was interested in the actual treasures this time, but that’s completely okay. I set up the activities (sometimes with help), and they decide how to use them 🙂