A Lava lamp is probably one of the funniest science experiments that can entertain your kids and teach them about liquid density. Isn’t it cool that you can explain to them how some liquids are heavier than others while creating a brilliant piece that they can later place on their bedside table?
There are so many simple things you can create to upgrade your home. You can make picture frames, doorstop and even lampshades. Or you can make a lava lamp. It’s a very simple science project and an indoor activity. But it’s also a great gift for a loved one or you! So, are you ready to see how you can make your own? This guide will show you all the steps!
How does a lava lamp work?
It’s all about two different liquids: Oil and water. These liquids have different densities and polarities and can’t mix with each other. Do you know what are these? No? Let’s see!
Have you ever heard that water is denser than oil? What does this mean? It means that when having the same volume as these two liquids, water is heavier than oil. That’s why oil floats on top of the water.
We mentioned above that water and oil don’t mix. How come? They are made of different particles and molecules. And that’s where polarity makes its appearance! Polarity is connected to the fact that a molecule has a positive charged end and a negative charged one.
Water molecules are polar, whilst oil molecules aren’t, but they have a shell of negative charges. So polar molecules can only dissolve in a polar solvent, and non-polar molecules can dissolve in non-polar solvents. That’s the reason why oil can’t dissolve in water.
But how exactly does such a lamp work? Water is heavier than cooking oil. If you add these two liquids in a container, water will sit at the bottom of the container, and oil will be at the top, above water. Now, if you heat the container’s bottom, water will absorb the heat and expand. As it expands, it loses its density and becomes lighter than oil. While water becomes lighter, it will rise and stay above the oil.
Before we continue explaining, we’ll have to tell you some more useful information. First, for better results, you should add a few drops of food colouring. Food colouring has the same density as water. Thus, it will sink, won’t colour the oil, and you’ll be able to observe the science experiment. You’ll also need to add tablets known as Alka Seltzer. These tablets react with the water and create carbon dioxide bubbles.
Now, as the water rises, it cools down and becomes denser and therefore heavier, and it finally starts sinking, reaching the bottom of the container again.
A light bulb is used to heat the water. But, as you have probably noticed, all the procedures in slow motion. Why is that? Because heat absorption and dissipation are slow processes and the density changes are slight.
Step-by-step guide: How to make a lava lamp
Are you ready to find out how to DIY a lava lamp experiment? It isn’t difficult at all. You can make a homemade one with ingredients you already have in your cupboards.
For the lava lamp experiment, you need:
- A clear glass container (you can use empty water bottles)
- Mineral or vegetable oil (baby oil works fine as well)
- Food colouring
- Alka-Seltzer tablets
Note: Instead of these types of tablets, you can use:
- A mixture of baking soda and citric acid
- Soda and vinegar
- Table salt
Once you’ve got all the ingredients, you can proceed with making your own lamp. First, here’s what you have to do:
- Fill 1/3 of the container with water and then add oil to fill it.
- Wait a few minutes until the oil separates from the water and stays at the top.
- Add a few drops of food colouring. Choose your favourite colour. As we’ve already said, the food colouring is water-based. What does this mean? That it’ll pass through the oil, sink and colour the water.
- Next, break a tablet into smaller pieces and drop one at a time into the container.
Note: Instead, you can use sodioume bicarbonate and citric acid. Mix 1 tablespoon of soda with 2 tablespoons of citric and stir very well. Then, add the soda-acid mixture into the container.
Or you can also use baking soda and vinegar (acetic acid). When these two ingredients mix, a chemical reaction happens. They begin to fizz, and they create carbon dioxide gas. Before you add water to the container, mix it with 2 heaping tablespoons of baking soda and add the cooking oil and food colouring, as mentioned above. Finally, slowly, pour vinegar into the container.
Also, if you don’t want to use citric acid, you can use salt. Add salt (don’t be stingy) to your liquids. Salt is a heavy ingredient. While falling, it will pass through the oil, and it will carry some into the water. As soon as the salt dissolves in the water, oil molecules will float up to the top. You won’t have the same results as using Alka- Seltzer or soda combos, but you’ll still see gas bubbles.
5. Now, you can watch the lava lamp experiment in action. See the coloured water bubbles erupt, and the blobs of the coloured water fall back to the bottom. You’ll need to add more tablets while reaction slows down.
Extra tip: If you use a container with a lid, leave the lid off while the reaction starts.
How to make a “glow in the dark” lamp
How would you feel about a “glow in the dark” one?. You’ll enjoy it even more! Are you ready for this craft? There are two different methods that you can choose from. Check them!
For the 1st method, you will need:
- A clear plastic bottle
- Warm water
- Vegetable or baby oil
- Glow in the dark gel, or glowing water
- Alka-Seltzer tablets
- Blacklight (optional)
The procedure is almost the same as making a simple lava lamp, but with some slight differences.
Let’s see the steps to follow:
- Pour some gel or glowing water into the bottle. Then, add a big spoonful of the glowing liquid.
- Then, add warm water. You need to fill 1/4-1/3 of the bottle and wait until the gel dissolves.
- After that, add the oil. Just make sure that you leave some space empty at the top.
- Turn off the lights and turn on the blacklight.
- Now, break the tablet into smaller pieces and add one piece at a time. Enjoy the bubbly reaction!
If you can’t find glow in the dark gel, there’s another way to make this fun science experiment.
Here’s what you need:
- A glass jar
- A cup of vegetable oil
- 2/3 cup of water
- Alka-Seltzer tablets
- 2 Glow sticks
- Scissors or knife
Once you’ve gathered your ingredients, follow these steps:
- First, add a cup of oil and then 2/3 of water.
- Leave the water to fall into the bottom of the jar and wait for 30 seconds.
- Then, crack a glow stick and shake it until it’s completely turned on.
- Hold the glow stick upright and cut the top with a knife or scissors.
- Empty the stick into the jar without stirring the liquids. Repeat the same process with the second glow stick.
- Finally, break a tablet into smaller pieces and add a piece at a time.
Making a lava lamp isn’t time-consuming and costs almost nothing as you can use ingredients you use in your everyday life. You’ll only need 5 minutes of your time and this easy tutorial to turn it into a fun science project for your kids or make a special gift for your loved ones. Make a box out of paper, put in your homemade lamp and give it to your specials. They will love it!