You might think sink or float experiments are just for small children, but there are some great investigations you can do with older children along the same theme.
Sink or float investigation for little ones
A large bowl of water
Objects to test (anything you like, but good to pick some solid and some hollow objects)
Fill the bowl or container about 2/3 full of water.
Gently place the objects on the water, some objects will float when you place them on the water gently, but sink when you drop them.
Can you predict which objects will float and which will sink?
Can you design a table to record your results?
Why do some things float and some things sink?
Whether an object floats or sinks depends on its density. Density is how tightly packed the material inside an object is. Just because something is heavy does not mean it will sink. For example, ships are very heavy but not very dense so they float.
Something else to try would be to make a boat from plasticine and show how marbles or something similar sink on their own, but hopefully float when inside the boat.
More science experiments for kids
Make boats with recycled materials and test to see if they sink or float. Try adding extra weight to investigate how much they can hold without sinking!
Make an egg float using salt.
Edventures with Kids tests different fruits and vegetables to see if they float or sink.
Can you think of any more sink or float experiments for us?