Help your kids make a cool lava lamp at home

Bubbling blob lava lamps have been in fashion since the 1960s while it comes to kids' room décor. Lava lamps light up their room with a groovy effect making it ideal for a sleepover or movie night with friends at home. A typical lava lamp is filled with coloured wax globules that float around in a transparent liquid under light effects. It’s a great item to explore the principles of chemistry and physics in the most fun way. A DIY lava lamp can be made by your kids using simple household supplies. It’s also a great at-home activity to teach kids about kinetic molecular theory. Here’s how your kid can make a safe lava lamp dupe at home. 

What you need  

• Clear plastic bottles or mason jars 
• Water 
• Vegetable oil 
• Eno or mint tablets, a mixture of baking soda and citric acid will work too 
• Liquid food colouring 
• Vinegar 
• Baking soda 

Step-by-step guide 

• Fill the plastic bottle or mason jar with water up to a third of the way.  
• Fill the remaining container with vegetable oil almost to the top. The oil will float on the surface of the water.  
• Add a few drops of food colouring of your choice. Because the food colouring is based on water, it will sink and colour the water.  
• Break a mint tablet into small pieces and drop one at a time into the flask. 
• If using the mixture of citric acid and baking soda, mix 1 spoon of baking soda with 2 spoons of citric acid slowly pouring the mixture into the container. 
• Baking soda and vinegar can be mixed as well. Take 2 spoons of baking soda and water and add them to the container. Now add the oil and colouring. Slowly add the vinegar to the container at this stage. 
• Watch your lava lamp sizzle with activity, keep adding Eno tablets into the container gradually. 
• If using a lidded container like a mason jar, make sure to keep the lid open when the reaction takes place. You can close the jar once the bubbles are settled. Keep adding more tablets to start the reaction every time. 
• To clean the container, properly dispose of all the contents wiping out the oil completely.  

How does kinetic molecular energy work in a lava lamp? 
It is common knowledge that all matter is made up of molecules in a constant state of motion, owing to the gas spaces between them. These molecules contain kinetic energy, which determines motion and is temperature-dependent. Molecules have more energy when it is hotter, and when they have more energy, they move faster.  

The movement of molecules is also dependent on density. Remember the common practice of throwing a coin in a pond or water fountain? Heavy objects like coins sink in the water due to their molecular density. In the same way, the globules in the lava lamp sit at the bottom of the lamp at room temperature. When an electric lamp is turned on, the globs heat up, moving faster in the surrounding liquid. When the molecules cool down, they lose energy and contract. The molecules become denser than the surrounding liquid and begin to sink, when they reach the bottom the whole process continues.