It razzles, it dazzles, and it’s absolutely magical – this Halloween lava lamp science experiment is a must-try. Your little scientists will beg to do this every year.
Why try this Halloween lava lamp science experiment?
Well, I am so glad that you asked! 😉
- It’s easy
- It uses simple supplies
- It’s exciting for kids and adults of all ages
- Kids can help set it up
- Clean-up is easy
We first made Halloween lava lamps with our preschoolers many years ago, and it quickly became an annual Halloween tradition.
Sometimes, we even call it “witch’s brew” for an extra layer of fun and silliness.
Related: A GIANT 10-foot Halloween coloring banner is the best addition to your Halloween fun (and it’s perfect for kids of all ages!)
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- Alka Seltzer tablets – I used the generic brand
- Liquid watercolors or food coloring
- Vegetable oil
- Tall clear containers – Vases and mason jars work great, too
Begin by filling your clear containers with water and adding a splash of color to each.
Next, add the oil (I add a little less than half the water). Before adding it, invite your child to predict what they think will happen when the oil is added to the container.
- Will the oil and water mix?
- Will one of them float?
- Will they make any sounds?
Once the oil is added in, the last step is to add in half of an Alka-Seltzer tablet. Once again, before adding it in, invite your child to predict what they think will happen.
- Will it explode?
- Will there be any sounds?
- Will it change the water or oil?
Prepare to ooh and aah while you observe the oil and water create a super cool lava lamp effect.
What do kids learn from a Halloween lava lamp science experiment?
When the water and oil are poured into the same container, they do not combine (which is new to young kids and fascinating).
In doing this experiment, kids are:
- Making predictions
- Observing oil and water not mixing
- Learning the differences in density (oil is less dense, so it floats on water)
- Practicing fine motor skills
- Watching the reaction between the liquids
- Realizing that the colors don’t mix with the oil
Looking for more science experiments to try? We love these:
- Halloween Frozen Hands Science Experiment
- Oobleck Color Factory
- Dancing Apple Seeds Science Experiment
- Oil and Water Experiment for Kids
What is the science behind Alka Seltzer lava lamp?
The Alka Seltzer tablets create little bubbles of carbon dioxide gas. The bubbles carry the water to the top, at which point they pop, and the water sinks back down.
Check out this post to learn more about the incredible science behind this experiment.
Kick the Halloween lava lamp science experiment up a notch
I have often shared that I am forever a “more is more” person – ESPECIALLY when it comes to fun experiments with kids.
After experimenting with only using half of an Alka Seltzer tablet at a time, experiment by adding a whole tablet.
Or maybe even two.
OR MAYBE EVEN THREE.
Have fun, friends!
Any that can safely use the materials. If doing this with young kids, consider using plastic containers instead of glass.
For longer than you might think! Breaking up the tablets into smaller pieces allows for the project to go on for longer periods of time, too.
Absolutely! You can use any size jar you want.