We are thrilled to bring another density science experiment to you. If you liked our fireworks in water experiment
, you will love making this lava lamp at home.
My daughters and I were super excited to do this experiment after watching many videos. We wanted to make our own version of it. The neighborhood chemist was short of the fizzy tablet which delayed our experiment for a while.
On a Friday, my husband brought home the long awaited Fizzy tablets. That made us all set to do the lava lamp at home.
Science Concepts Discussed
Density of liquids, Fizzy Science
Who is it for
When we did this experiment, my elder one was 7 and the younger daughter was 5. Density is a good concept to be explained for older kids. So the experiment would be well suited for kids of 5 to 6 year olds
or older kids of aged 7+
What we need to make your own lava lamp at home?
Except the fizzy tablet, you might have all the required materials at home
- Vegetable Oil
- Food color of your choice (red one looks better)
- Fizzy Tablets / Effervescent tablets
- Glass container
- Black light (optional – for extra visual effect)
Let’s get into the lava lamp experiment.
DIY Homemade Lava LampStep 1:
Pour water in your glass container. Fill just 1/4th of your container. We used regular tea cups. You can choose the size of the container based on your preference. Longer the height of the container, better the effect.Step 2:
My younger daughter prefers to play with colors, so I let her add food colors to the water that we already added. You can choose your own color, I liked red and green as they bring out wonderful blobs. Step 3:
Just to be sure, we stirred the food color & water mixture a bit with a fork. Normally, the food colors get dissolved in water instantly. If you are using powdered food colors, this step might come handy to mix the food color well with the water. Step 4:
Next, my elder daughter poured oil on top our food color water mixture. Fill up the 3/4 of the container with oil. This is where all the action is going to happen, so it is important to have enough oil to show the blobs clearly. Also be gentle with pouring oil. Let is sit for a few minutes so that all the bubbles would settle down and your kids can clearly see the oil on top of the colored water. Step 5:
Now we are ready for action. I let my elder daughter to drop the fizzy tablets into the solution that we prepared. The tablet would slowly dive in and reach the colored water at the end. That’s when the fun started. We started seeing beautiful blobs coming out of the water and reaching the top. Seeing the action, my daughter quickly put tablets in all four mixtures that we prepared.
The kids were thrilled to see the blobs. Finally we did it. We made our own home made lava lamp.
My daughter got a good idea – what if we see this with black light? Why not? Tisha quickly brought the black light torch and switched it on. The kids started jumping on joy watching the lava lamp in UV light.
We were very happy that all turned out well.
I let the kids enjoy the show for a while. Then I started explaining the science concepts behind the blobs.
Science Behind Lava Lamp
I always prefer to ask questions before explaining the science behind any activity.
As a mother of curious girls, we should always encourage our kids to ask as many questions as possible.
Here are some of the questions and the suitable answers that you can use to discuss with your little ones.
What happens when you make a homemade lava lamp?
When the Fizzy Tablet added with water, it combines with water and creates carbon dioxide. The released carbon dioxide gas bubbles rise up in the oil while carrying the food colored water. You should see big blobs initially due to the fastness of this chemical reaction. Eventually, the chemical reaction will slow down and the food colored water comes back down to its original place.
Though chemistry plays a major role, the underlying science concept for the blob to come out is density of materials. Density can be defined as amount of material that can be fit into given space.
Which is heavier – water or Oil. Why is it heavier?
Water is heavier than oil. You could do a simple experiment. Measure up 500 ml of water and 500 ml of oil in two similar containers and weigh them up in a kitchen scale. Your kids can visibly see that the water is heavier (in mg / lbs) compared to oil.
Water is heavier because the density of water is higher than the oil. In other words, the molecules of water are tightly packed compared to oil. This is why oil floats on top of water.
Why does food coloring mix with water and not oil? Why does water and oil not mix?
When food color is mixed with water, it instantly mixes with water. The concepts work more like magnets. Don’t we remember, the opposite (north and south) poles attract each other? Similarly water particles have negatively charged oxygen and positively charged hydrogen. They both attract each other due to polarity.
On the other hand, oil does not have any charge (i.e. no positive or negative charge). That is the reason why it couldn’t mix with water.
What is meant by fizzing tablets?
Effervescent tablets / Fizzy tablets are uncoated tablets. They have typical kind of substances that would instantly react with water (if mixed) and create carbon dioxide as a result of chemical reaction. Do you know, you can create a carbonated liquid just by using fizzy tablets?
How does Alka Seltzar affect water and oil?
Alka Seltzar when mixed with water produces carbon dioxide. The released gas forms a bubble and tries to reach the top as a result we get blobs.
What is Alka Seltzer composed of?
Aspirin, Citric Acid and Sodium Bicarbonate are the components of Alka Seltzer. Actually the sodium bicarbonate and the citric acid what mixes with water and creates carbon dioxide.
How do you make a lava lamp without Alka Seltzer?
There are options to use salt to make a homemade lava lamp. Otherwise you can simply use citric acid with baking soda in 1:2 ratio to substitute Alka Seltzer.
Can you make a lava lamp with olive oil?
Yes, ofcourse, you can use any vegetable oil. All we wanted to show that Oil floats on top of water.
How much vegetable oil do you put in a lava lamp?
I prefer to have atleast 3/4 of the container. So for 1 portion of water, I would add 3 portion of oil for a lava lamp.
Can you leave lava lamps on all night?
The original lava lamps are not safe to leave on all night. Because the original lava lamp produces heat and it is not safe to keep the heat rising. On the contrary, the homemade lava lamp eventually will die off after some due as the chemical reaction would stop. i.e. once the citric acid and sodium bicarbonate goes off after the chemical reaction, the blobs will slowly die off. Because, there are no more carbon dioxide produced. And the colored water will come down and settle down with the rest of the water.
Are lava lamps supposed to get hot?
Real lava lamps do get hot. Typically, you should not use the lava lamp for more than 8 hours at a stretch.
Can you touch a lava lamp?
Real lava lamps are normally hot. So it is not safe to touch a real lava lamp.
Caution for parents ...
All the experiments in our blog requires parents guidance and support. Adults should always overlook when the kids try out any science experiment.
Small kids are always attracted to colorful liquids. Though there is nothing harm in tasting food colored water or vegetable oil, there is significant side effect of tasting fizzy tablets. KEEP THE TABLETS AWAY FROM YOUR KIDS. Serious Precaution:
Effervescent Tablets (Fizzy Tablets) are not safe for children
. In any situation, we advise not to let your kids to taste or consume the tablet. Consuming Fizzy Tablet might cause nausea, dizziness or drowsiness. If face such condition, contact your physicist immediately.
Though the lava lamp looks incredibly cute, keep off the little ones from drinking or tasting it.