Todays experiment is very simple, but hopefully fascinating for even very young children.
What you need
- Transparent containers
- Water ( hot and cold )
- Substances to try and dissolve eg. sugar, coffee, pepper, sand.
Add a teaspoon of whichever solid you are testing to a glass of cold water and a glass of hot water, stir and observe the difference.
Look to see if the solid dissolves in the hot water and cold water and if one is better than the other.
Can you design a chart to record your observations?
The Science bit
Things like salt, sugar and coffee dissolve in water. They are soluble. They usually dissolve faster and better in hot water.
Pepper and sand are insoluble, they will not dissolve even in hot water.
For older children
Everything is made of particles which are always moving. When a soluble solid ( solute ) is mixed with the right liquid (solvent), it forms a solution. This process is called dissolving.
Two things that affect the speed at which the solid dissolves are temperature and the size of the grains of the solid. Caster sugar which is made of fine particles will dissolve quickly, but bigger sugar particles will take longer.
Solids dissolve faster in hot water as in hot water the water molecules are moving faster, so bump into the solid more often which increases the rate of reaction.