Put a coloured substance (like food colouring) into a clear one (like water)
Time how long it takes for all the liquid to be the same colour.
Change the temperature of the liquid and make observations.
The higher the heat, the more kinetic energy meaning the colour moves through the liquid faster.
Cut two roughly equal pieces of potato and weigh them.
Put one in distilled water and one in salt water.
After a given amount of time weigh them.
The one in salt water will have lost mass as the water in the potato moves to the more highly concentrated salt water. Where as in the pure water the potato will have gained mass as it was less dens with water.