Thursday, 3 March 2011


As much as possible, science teachers would want to do activities in the class, which are exciting but less expensive. Especially when the kids are asked to bring the materials needed and turned out to be difficult to find or too much for the wallet, the thrill to do it would eventually fade.

There are many lava lamps available in the market but why not make your own and use of materials that one can easily grab in the cupboard or take out from the medicine drawer or buy from the nearest supermarket. Today I am sharing to you how to make a LAVA LAMP which I have done myself several times in science club activities or classroom demonstrations.
This activity can be conducted in a secondary class or entry level in college as a demonstration. There is in fact no pre requisite knowledge to do this but common sense always takes part in science experiment to appreciate the result. But it is intelligible and challenging to start mapping concepts:

What happens when you mix oil and water?
What happens when you put a drop of food colouring into the mixture?
What happens when you put an antacid into the mixture of water and oil?

Materials Needed:

Small plastic bottle with cap
Vegetable oil
Food dye/colouring
Antacid (ex: Alka-Seltzer)
Paper towel


1.Measure about 200ml of vegetable oil and pour into the plastic bottle.
2.Fill the remaining space of the bottle with water.
3.Add small amount of food colouring to give the water a darker shade.
4.Break up one antacid tablet into tiny pieces.
5.Drop bits of antacids into the mixture of oil and water and observe what happens.
When the bubble stops, continue to add more bits of antacid.
6. When you are done putting all the antacids and the reaction has stopped, screw on the bottle cap.
7. Tip the plastic bottle back and forth and watch what happens.  The tiny drops of liquid would join together and produce a big lava lamp ball.


Oil and water molecules do not mix.  When the water is poured into a plastic bottle with the oil, the water would descend to the bottom because water is heavier than oil.(oil is less dense than water). Not even if you insist to shake it up thoroughly.  We call it immiscible – they don’t dissolve in each other.

The oil might break up into small drops, but it does not mix with the water.  However, the food dye will mix with the water.  On the other hand, the antacid reacts with water to form tiny bubbles of carbon dioxide.  These bubbles attach themselves to the beads of coloured water and cause them to float to the surface. When this bubbles break up, the drops of coloured water settle back to the bottom of the bottle.

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