Science Projects for Kids: Alka Seltzer Rockets


Sometimes the simplest experiments get the biggest bang! And by bang, I mean capture your kid’s attention and keep them entertained for a whole afternoon. And by simple I mean raid your grandma’s medicine cabinet and steal a few Alka Seltzer tablets. Teach your kids about physical vs chemical reactions while shooting off rockets.

Homemade Rocket Experiment

Two experiments are involved in this project. The outcome is the same—lids bursting off the film canisters with a rocket burst of gas. However, the reaction inside the canisters is different. Check for more info about this experiment.


  • Clear Soda Pop or Plain Seltzer Water(less sticky!)
  • Alka Seltzer Tablets Broken into Quarters
  • Pitcher of Water
  • Small Containers like Film Canisters, with Tight but not too Tight Fitting Lids

Steps to Creating a Physical Reaction, Releasing CO2 Gas From Soda Water

  1. Gather up a few neighborhood kids, we were happy it was a sunny warm day because this is NOT an indoor experiment! And safety glasses are suggested. It’s a perfect activity for a summer beat the boredom activity.
  2. Begin the physical reaction. Fill the canister with the soda water, start with ¼ full and increase each time to ½ and ¾ to test how well it works with varying amounts.
  3. Cap your container and shake the heck out of it! Holding it with the lid facing away get ready for the POP! Note how far the rocket launched and try it again with a different amount of soda.

Steps to Creating a Chemical Reaction, Combining Alka Seltzer and Water Releases CO2 Gas

  1. Grab those same neighbor kids and line everyone up with a quarter piece of Alka Seltzer in their containers.
  2. Add varying amounts of water and cap the lids.
  3. Set the canisters down and wait  for the lids to pop off.  Watching the kids is more fun than the experiment!

Steve Spangler the ‘Making Science Fun’ expert explains:

“In both cases, carbon dioxide gas builds up so much pressure the lid is forcibly launched. With an Alka-Seltzer tablet, the CO2 is produced as a result of a chemical reaction. With the soda, the CO2 is produced as a result of vigorous shaking. This provides a good contrast between a physical and chemical change.”

Steps to Creating a Game From This Experiment

My kids brainstormed ways to use the CO2 rockets as various games set to a "water olympics" theme, including:

  • Draw a line on one side of your driveway. Then take turns attempting to make your lid fly past the line.
  • Draw several circles at differing distances and try to make your lid land in each one.
  • Time 4 contestants Alka Seltzer rockets, and the first lid to fly off wins!

What new game ideas can your kids come up with, using a homemade CO2 gas Rocket?

The MomItForward teaching science series is brought to you by, more great ideas for teaching your kids science!

In a former life, Carissa Rogers was a molecular biologist. In her current life, she is the chief researcher of bloggy karma, parenting dos (and some don’ts), new recipes, and for spice she pretends to be a photographer. She started blogging in February of 2008 and publishes her good & crazy thoughts on Find her on Twitter and Facebook.


3 Responses to “Science Projects for Kids: Alka Seltzer Rockets”

  1. [...] This post was mentioned on Twitter by MomItForward, Melissa Dawn Lierman, Troy Pattee, ZarBee's Cough Syrup, Troy Pattee and others. Troy Pattee said: RT @MomItFoward Science Projects for Kids: Alka Seltzer Rockets: Sometimes the simplest experi… [blog post - mom] [...]

  2. Billy says:

    Hey! Thanks for these very cool experiments. I’ve found another very useful site for kids science experiments to be,

    Kids Science Experiments

    I find the best way to keep kids interested in science is to let them perform the experiments themselves.

    Thanks again!

  3. Hi friends,

    It is our duty to prepare kids for their future, so we should offer science games for kids that help student to develop creative thinking in pursuit of excellence. Thanks a lot.

Leave a Reply

Web Statistics