You will need:
Fill a glass with warm water. Put a spoonful of sugar in it and stir.
What happens to it?
Try this with a spoonful of salt. What happens?
What happens if you use pepper?
You can have a go at using other things-ask your grown up what you could try.
What has happened to the substance you have put into the water?
When something 'disappears' in water, we say that it has dissolved. Some substances dissolve in water, some do not.
Next week we will see if we can make them re-appear!