This Lava Lamp Experiment is so cool to look at and even cooler when you watch it glow! This simple step-by-step picture tutorial shows you how to make lava lamps using 5 ingredients.
As always, all activities seen on the Fun With Mama website should be done under close adult supervision. Do not allow your child to put any of these materials in their mouth.
Lava Lamp Science Experiment
We love easy science experiments. Especially ones that require minimal materials, that are easy to clean up, and have a wow factor (like the skittles science experiment.) The first time we tried this simple science experiment my kids were really blown away by the results.
This homemade lava lamp science activity was just as exciting and will teach children more about science concepts like chemical reactions, density, and polarity through a hands-on activity.
Before you begin this easy science experiment, ask your child to make a hypothesis.
Some questions to ask your child could be:
- Do you think the oil and water will mix?
- Will the food coloring mix into the oil and change it’s color?
- Will the food coloring change the color of the water?
- Do you think the tablet will float at the top? Or will the tablet sink?
Suggested Supplies To Make Your Own Homemade Lava Lamp:
- Alka Seltzer Tablets (which is sodium bicarbonate). You will use 1 whole tablet for 4 cups.
- Food Coloring
- Cheap Vegetable oil ( I used Canola oil)
- A clear container – You can use glasses, soda bottles, empty water bottles, or heavyweight cups.
Most of these supplies are common household items you likely already have at home.
Video Of The DIY Lava Lamp Experiment In Action
How do you make a lava lamp experiment?
Begin by making sure you have all items needed for the experiment.
I like to place our activities on trays. This helps prevent spills on our floor and carpet.
Step 1: Add 1/4 cup of water to 3 of your empty cups. Add a few drops of food coloring to these glasses and mix.
Step 2: Fill the other 3 empty cups with 1/2 – 3/4 cup oil.
Step 3: Pour the colored water into the oil containers.
This part is pretty to look at.
You will see that the colored water will drop to the bottom of the glass and the oil will move to the top of the water.
You can explain to your children how oil and water do not mix because they have a different density… that is why you see the separation of colors.
Step 4: Break your Alka Seltzer tablets into 4 pieces. (you can use more of the tablet per glass if you prefer.)
Step 5: Start throwing the antacid tablets, which are the Alka Seltzer tablets, into the mixture slowly.
Watch the cool lava lamp effect. Who knew blobs of colored water could be so pretty?
When the colorful blobs stop bubbling, the tablet is dissolved.
Make it glow
Go into a dark room with a flashlight. Position the flashlight under the lava lamp and watch how it glows. The lava lamp bubbles look SO spectacular.
The science behind the Lava Lamp Experiment
Well, how does the lava lamp experiment work? Here is the science behind the experiment and the terms you should know.
Density refers to how compact a substance is. Denser liquid sinks. The higher-density liquid will sink below the one with lower density.
The oil floats on top of the water because the density of oil is less dense than water (so it is lighter.)
Food color has the same density as water, which is why it only mixes with the water and doesn’t mix with the oil.
Polarity means that a molecule has a positive charge on one end and a negative charge on the other end. Water molecules can connect their positive ends to another water molecule’s negative end. They act like magnets and stick to each other.
The water and oil do not mix because the oil molecules are non-polar, so they are not attracted to the water molecules. Water is a polar molecule. They are made up of highly charged compounds that are hydrophilic.
Alka Seltzer tablets are made up of sodium bicarbonate as the base and citric acid. It then becomes sodium citrate when mixed with water.
When the tablet is added to water, it sinks to the bottom and then starts to dissolve. The acid and the base react to form a gas called carbon dioxide. This gas is released in the form of carbon dioxide gas bubbles.
Gas or air is lighter than water, so it floats to the top.
Some of the colored water is brought to the top with the air bubbles. When the bubbles of carbon dioxide gas pop, the air releases out of the colored water blobs, and the water droplets get heavy and sink.
It will continue to do this until the tablets dissolve.
I hope you enjoyed this fun DIY lava lamp activity and that your children have gained some knowledge about liquid density.
You can adapt the activity to make it seasonal by using seasonal colors. For example, make a Christmas lava lamp by using 2 glasses. One red one and one green one.
Are you looking for more fun and easy science activities for kids of all ages? Check out one of these fun activities:
Don’t forget to check out more of our science experiments for kids.
Check out these 29+ Best Science Fair Project Ideas.
This post was originally published on February 8, 2018.