Introduction: Alka Seltzer Rocket Activity

About: In a valiant attempt to keep myself from dying of boredom, I create.
I recently shared the idea of this rocket with another Instructables member.  So I thought it was about time I wrote it up.  I remember the first time I did this with Cub Scouts, I kept calling the canister a rocket, and they called it a canister, until the first time it flew. When Cubs was over that day, one rocket had been left behind. About an hour later a Cub came looking for his "Rocket". It's been a success ever since.   It is also a great demonstration on how gases can build up in a container and keep building up until released (that’s how we get the pop). I will share the basic rules that I have put in place for safety and organizational purposes.  So, this is the Alka Seltzer Rocket Activity.

Step 1:

Clear empty 35 mm film canisters with the lid that fits on the inside of the canister.  (These are getting hard to find.  Used to be you could go to places that developed film and they would just give them to you.  Two websites that carry these are: and  or just Google it.
Alka Seltzer tablets (save a small fortune and buy the genetic brands +/-$4 for 36 tablets) Water
Stickers and or
Color permanent markers

Step 2:

Advance preparation:  Break each effervescent tablet into 4 pieces.  Place them in a bowl to distribution.  Have a container of water for filling each rocket.

Step 3:

Gather your group of people around you for this activity.  Give each person their own film canister, only call it a rocket.  Let them spend time decorating the rocket with stickers and markers.  Remind them to put their name on it.
Have a hard surface set apart as the launch area.  It would be fun to put caution tape or some other marker around the area, but not necessary.    Show the participants how to get their rocket to fly.

Step 4:

They then take their rocket to one station where they can fill the body of their rocket about 1/3 full of water.
They then take their rocket to another station to pick up the ¼ of Alka Seltzer table.  Tell them to keep the tablet dry and separate from the rocket until they reach the launch pad.

Step 5:

At the launch pad, put the tablet into the water, put the lid on the rocket and place the rocket lid side down on the launch pad.   
Take 4 steps back from your rocket and watch.
Pop, the rocket flies into the air.  It is so much fun that they will want to do it over and over without stopping until you run out of fuel.  This is my grandson, and his first time flying an Alka Seltzer rocket.  Once we made the little video, he stayed outside blasting off his rocket until he was out of fuel.  His evaluation was: FUN!   Enjoy!
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