One of my kids’ favorite activities to explore chemistry is to make film canister rockets. The hardest thing is to get the film canisters because most of us don’t have these laying around anymore. However, you can get them from a myriad of different places such as Amazon or Science Bob. You can use them over and over, unless you lose them on the top of your roof, which has happened to us!
Kids of all ages – from 3-16 – have enjoyed this project as well as all adults.
Materials you need:
- Film Canisters – you need a minimum of 1, but I suggest getting 10-15, as you will lose some if they fly high. Plus you can do multiple ones at the same time to experiment
- Alka-Seltzer Tablets – I use just the generic ones, the cheaper the better
- Safety Goggles – in case you get too close to the rockets
- Corn Starch – to leave a cool rocket trail (not necessary, but fun)
Materials you MAY want to have:
- Baking Soda – for additional experiments
- Toilet Paper – for additional experiments
- Vinegar – for additional experiments
- Various other liquids and bases you can add to the containers
- Take the corn starch and fill the canister up about 1/3 of the way
- Add Water – the first time I added so the canister was 2/3 of the way full but after each time experiment with the amounts
- Break an Alka-Seltzer tablet into 4 pieces – again you can experiment with how much you put in
- Put the Alka-Seltzer tablet into the contain and QUICKLY put the lid on tight
- Flip the container upside down and put on the ground
- Move away from the rocket
- Watch it soar!
Depending on how much corn starch/water/Alka-Seltzer you put in will determine how long it will take to explode, but with the original amounts I listed above, it is about 20-30 seconds. It seems like a VERY LONG time with a 3 year old, but once you do it the first time, it is exciting to wait. With about 1/3 each of cornstarch and water and a ¼ tablet, the canister reaches my 2nd story roof. They move so fast I couldn’t get a picture, but here are the tops and the spray pattern when it launches.
Experiment with different amounts of water, tablet size, and other things like baking soda/vinegar. One site I saw this experiment on wrapped the Alka-Seltzer in a tiny amount of toilet paper. There’s no end to experimenting with different types of reactions.