The perfect summer afternoon science experiment has arrived: Alka-Seltzer rockets! What better way to get the kids outside than with rockets they can make themselves!
Similar to baking soda and vinegar science, this engaging activity really puts on the pressure…and the results are a real blast!
You will need:
- Film canisters with lids or any other small plastic container with a tight-fitting lid
- A package of Alka-Seltzer
*Important to Note: All were surprised on how far these little rockets can fly, so make sure small inquiring minds step back and wear safety goggles. For certain, this activity must be adult-supervised.
Fill the film canisters about 2/3 full with water. Change a variable by adjusting the water temperature to see how the experiment changes. Does warmer water make a difference? Have the kids write down their process and findings.
Next, break up your tablets in fourths. That’s all you need for a big result!
You will see the reaction start immediately as soon as the tablet is dropped in. Secure the lids on tightly and quickly. Flip them over onto a flat surface so the cap is facing down. Step back!
Pop! Pop! Fizz! Fizz! The rockets will shoot up high at different rates. Again, make sure the lid is on tight or the water will simply leak out. Your little rocket scientists will surely want to repeat this again and again.
What is the science behind why these rockets take flight?
Bubbles and fizz are what make this popping rocket trick a real blast. Inside a tablet of Alka-Seltzer are the ingredients of citric acid and sodium bicarbonate (the fancy name for baking soda).
When a tablet of the medicine is dropped in water, the acid and baking soda react to produce carbon dioxide gas. The pressure builds and… blast off! The lid is the path of least resistance for the pressure. It’s simpler for the chemical reaction to pop off the weak lid rather than bursting through the stronger sides and bottom.
Sir Isaac Newton’s Third Law explains to us why the film canister and lid goes flying: for every action there is an equal and opposite reaction. The lid goes in one direction while the canister goes in the other. Have your kids think of different experiments they could do with this fun chemical reaction!
How far will your rocket fly?