Sink or Float
Some things float on top of water and some things sink to the bottom.
Drop a rock in water and it sinks. Put a leaf on water and it floats. It isn’t just about size: a big apple floats, but a small coin sinks! Scientists guess first, then test to find out.
Words to know
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Did you know?
- Apples float because they have lots of air inside.
- A giant ship is made of metal but floats because of its shape.
- Squash a ball of foil flat into a boat shape and it can float.
- It is easier to float in very salty water, like the sea.
Try it! Hands-on activities
Simple things to do together with stuff you already have.
Printables
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Read together
Stories to read aloud that go with this topic.
Talk about it
Questions to ask while you read, play or walk.
- Why do you think a big apple floats but a tiny coin sinks?
- Can you make something that sinks float? How?
- What else could we test?
For teachers
What this topic supports:
- NGSS 2-PS1-1 (preview): describe and classify materials by their properties
- NGSS K–2 science practice: plan and carry out simple investigations
- Head Start ELOF: Scientific Inquiry, predicting and testing