I am always looking for ways to combine fun and learning for my two preschoolers and I love it when I can find great science activities for young children. When I spotted a baking powder submarine toy for a few bucks in our local Marbles kids’ museum gift shop, I knew it would be a fun activity for bath time and we could experiment with the science behind what makes it dive and surface.
While this toy is designed to work in a container of water, we thought it’d be a much bigger hit in the bath tub!!
To make the toy work, we simply followed the directions printed on the package:
We pulled out the Periscope-Radar assembly and dipped the sub in water. Then we filled the bubble chamber with BAKING POWDER, not baking soda!
We replaced the Periscope-Radar assembly, held the sub under water, and shook it vigorously from side to side.
When you let go, the sub is supposed to start submerging and surfacing automatically. It didn’t start working right away, but we kept playing with it and eventually it did start working…and quite well!
We could even stir the water a bit and the submarine would cruise around in circles. It was fun to watch!!
What makes the baking powder submarine dive and surface?
Baking powder is made up of sodium bicarbonate (aka baking soda) and cream of tartar, which is an acid. When mixed with water, the two compounds react with each other producing carbon dioxide gas. The gas bubbles cause the sub to rise, and when the gas bubble escapes from the sub, it sinks again. The process can go on for awhile with the sub continuing to sink and surface over and over. For a more thorough explanation, see this page dedicated to baking powder submarines.
Another interesting fact about baking powder subs:
These toys in the past were commonly found in cereal boxes!
In addition to making a great science experiment for kids, the Diving Sub makes a great bath time toy. My little boy quite enjoyed using his imagination to pilot the sub all over the tub!
And we used the diagram on the packaging to learn all about the parts of a submarine! My 4 year old was very excited to be able to name all the parts on his new toy!
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