🪣 Sink or Float
Drop household objects into water and discover which ones sink and which ones float — and find out why!
Easy⏱ 15 minAges 4+Physical Science
🧰 What you need
🪣
Bowl of water
large
💧
Water
enough to fill
🪙
Coin
several
🔵
Cork
1
🪨
Stone
1
🍃
Leaf
1
🍎
Apple
1
🔘
Plastic bottle cap
1
🔬 Steps
- 1
Fill the bowl with water.
- 2
Look at each object and predict: will it sink or float? Write your predictions.
💡 Make it a game — give each object a 'sink' or 'float' vote before testing! - 3
Drop each object gently into the water one at a time.
- 4
Record what actually happened — were your predictions correct?
- 5
Try pushing a floating object down. What do you feel? What happens when you let go?
💡 You can feel the water pushing back — that upward push is called buoyancy!
🧠 The Science
Every object has a density — how much mass is packed into its volume. Objects denser than water sink; objects less dense than water float. A coin is very dense (lots of metal in a small space), so it sinks. A cork is very light for its size, so it floats. Buoyancy is the upward force water pushes on any object placed in it.
📚 Related Lessons
- 🌊 Water Around Us — Water covers most of Earth — in oceans, rivers, lakes, rain, and underground wells!
- 🏔️ Water Sources — Water comes from rivers, lakes, groundwater, rain, and dams — it travels a long journey to reach our taps!