In the experiment Hot water vs. warm water carried out by the students of Science in Action, 4ºSA and 4ºSB, last November we have worked on checking how the temperature of a liquid influences its density.

To do this, two Erlenmeyer flasks with the same amount of water are used. One flask will contain cold water and the other hot water. To make the experiment visual, two different dyes were used.When the two flasks are joined, so that the one containing hot water is on top, the colours are kept separate. On the other hand, when they are rotated so that the hot water is at the bottom, and the cold water at the top, the colours mix.

Why is does this happen?

Because hot water is less dense than cold water due to the activity of its molecules. When they are hot they have a lot of movement, make many collisions between them and have little density. To do this, two Erlenmeyer flasks with the same amount of water are used. One flask will contain cold water and the other hot water. To make the experiment visual, two different dyes were used.

As we have a great diversity of nationalities in the centre, we have thought it would be nice to make a recording of the experiment in different native languages, learning not only science but also that languages are no longer barriers but added value.

Many thanks to all the people who have collaborated, both students and teachers, to record and edit this experiment.