Do water molecules really move? If so, how fast and how slowly?
Things Required:
2 clear glasses
Food colouring
Cool and hot tap water
Medicine dropper
Directions:
Fill one glass with cool tap water. Fill the other glass with hot tap water. Now, quickly place one drop of food colouring in each glass. (Make certain that all the variables are the same. This means that the glasses should have the same amount of water in them and that the same numbers of food colouring drops are added. Controlling variables is important to make the experiment scientifically correct.)
This Is What Happens:
The food colouring spreads throughout the water in both glasses, but at different rates.
Science Behind It:
The cold water eventually becomes completely coloured because the water molecules are moving throughout the glass. But when the water is warmer (the hot tap water), the heat energy in it causes the water molecules to move much faster. This makes the food colouring spread out more rapidly.
You might want to chart, or keep a record of, how much time it takes for the food colouring to spread evenly throughout each glass of water.
