Fizzy, Fun Preschool Science Activity (Part 3: Alka Seltzer Lava Lamp)

Part 3 of my Fizzy, Fun Preschool Science Activity Series is at least as much fun for the adults as it is for the kids!  In case you missed my first two posts, Part 1 was Fizzing Sidewalk Paint and Part 2 was Fizzing Lemonade.  Part 3 (today's post!) is so much fun and so simple, that you might just have to do it a few days in a row!  I first discovered it on SLSmith's blog, and have loved it ever since.

So, just how do you make an Alka Seltzer Lava Lamp?  Help your kiddos...
  1. Fill a vase (glass water bottles look cool too!) about 2/3 full with oil.
  2. Add water until the vase only has 1-2 inches of air space left at the top.
  3. Add 5 drops of food coloring.
  4. Add Alka Seltzer (or the store brand version), 1/4 tablet at a time.  When the bubbles slow down, add another 1/4 tablet.  
  5. Experiment with any other additions you like.  My kiddos were particularly interested in sugar, salt, and teddy grahams.  I'll let you find your own experiments, but I'll tell you this...salt is more interesting than teddy grahams!
Check out this "action shot"...they just couldn't stay sitting down!

So, what's going on here?  I know you probably don't really care why Alka Seltzer makes bubbles, but since your kids will ask, I thought I'd give you something to work with!  Two of the ingredients in the Alka Seltzer tablet include sodium bicarbonate (aka baking soda) and citric acid.  When the tablet is dissolved, the ingredients mix together and carbon dioxide (bubbles) is released.  The bubbles mix the oil and colored water, which would otherwise remain separated.

Of course, my explanation for the kids came after the gasps and "Ooohs" and "Aaahs" and sounded more like, "The Alka Seltzer reacts to make the bubbles.  Carbon dioxide bubbles.  The bubbles stir the oil and colored water together."  And that's when Kaia asked if she could add sugar.


MaryAnne October 18, 2011 at 5:19 PM  

What a fun, visual science activity!

Jansen Family October 19, 2011 at 6:23 PM  

MaryAnne, We had so much fun with this one!


Alicia@ Mommy Delicious October 19, 2011 at 11:03 PM  

Oooohhh, this looks so cool. I'm going to have to try it one weekend with my son!

Marina October 20, 2011 at 7:21 AM  

Wow, this looks great! :)

Jansen Family October 20, 2011 at 8:15 AM  

Alicia, I bet he'll love it! My kids especially loved watching the bubbles start up after they added the Alka Seltzer!

Thanks, Marina!


Christina McComb February 26, 2013 at 9:40 AM  

I work as a substtute preschool teacher. We have to do a science project. so I figured we would try this thank you for a great idea.

Pranay Kotadia May 5, 2014 at 5:24 AM  

Whats the equation of the reaction that takes place in this experiment

Adnan May 19, 2014 at 5:47 AM  

nice your site thanks for sharing love you all team good work keep it up

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Unknown August 16, 2014 at 7:09 PM  

Just did this with my 4 & 6 yr old, both loved it! We tried sugar, salt, soap, borax and extra water. It was fun!

Laura Ward April 23, 2015 at 9:37 AM  

This was wonderful! My 5 yr old and 7 yr old had a blast adding different food coloring and watching the drops of color leak down the sides. We didn't have alka seltzer, but used efferdent instead, and it worked great... still bubbling away, in fact. The salt and sugar reactions got a lot of ooh's and aahs, too :) Thanks for a wonderful rainy-day activity!