Science Bite - Lava Lamp

Make your very own own lava lamp with this fun science experiment you can try at home or in school. 

Find out about different types of molecules and why oil and water just won't mix!

Always remember to ask a parent or guardian to help you.

What you'll need:

Instructions

Step 1 Rinse out your bottle with clean water and remove the label.  Now with the help of an adult fill your bottle about ¾ full with vegetable oil.  Cheap supermarket brand vegetable oil works just as well as more expensive brands.

Step 2 With the help of an adult fill your measuring jug with water and add a few drops of food colouring.  Best to do this over the sink. Carefully fill your bottle to the top with the coloured water then screw the cap on tightly and leave to settle for a few minutes

Step 3  Turn your completed ‘lava lamp’ upside down a few times and then place on the table.  Now you can watch the blobs of coloured water move through the oil! Why not try putting a torch behind your ‘lava lamp’ to light it up or maybe try different shaped bottles with different colours of food colouring.

Find out more

Why don't the oil and water mix?

Oil and Water are made of different types of molecules that are far too small to be seen. When you poured the molecules of water into the bottle, they settled to the bottom as a liquid. The molecules didn't fly apart and fill the entire bottle because water molecules stick together. Likewise, the oil molecules also stick together.

Different molecules have different tendencies to stick together. The oil and water did not mix. This shows that oil molecules do not like to stick to water molecules.  When two liquids do not mix they are considered immiscible.