The lava lamp effect experiment uses an indigestion tablet to slowly release gas that propels droplets of water upwards through a layer of oil. As the gas is released from the top of the reaction, the water falls back down through the oil layer as a result of its greater density thus resulting in a circulating effect of rising and falling water droplets.

Suggested teaching points

• States of matter
• Introduce the idea that reactions between solids and liquids can produce a gas (i.e. effervescence)
• Density
• Introduce the idea that chemicals of different physical properties do not mix (i.e. immiscible liquids)   

These are only suggested teaching points; other aspects of this experiment could be used to explain a number of other principles in science.

This file contains a set of detailed instructions, suggested questions, suggested improvements and disposal procedures for this experiment.

Lava lamp experiment instructions

Before attempting this experiment, please ensure that you have read the safety section in the document above and performed a complete risk assessment. If you have any questions, comments or feedback, please use these forms.