Experiment on water temperature and density [video]

Observe the difference in density between cold and warm water

application/pdf Water temperature and density experiment - activity sheet    

© Carol Brieseman, New Zealand /Hampton Hill School

Group activity

Duration: 20 min

Type of activity: experiment

Language: English

Materials required: a tray (or use a sink if one is nearby), two identical glasses, some cardboard, two  types of food colouring, very cold water, hot water


Follow the experimental protocol in this video step by step to show the difference in density between cold and hot water. 

Cold water is more dense than hot water and will sink to the bottom of the glass. This is what happens in the ocean. As the cold water particles are more compact, cold water is more dense and goes down to the bottom of the ocean. 

The activity sheet provides the instructions for the experiment and a discussion section.

Follow up with experimental activities:

Experiment on water salinity and density (12-18)

How to simulate heat transfer between water and sand (12-18)

Follow up with a booklet on seawater:

Seawater (12-18)

Test your knowledge:

Quiz yourself on the properties of water (9-11)