Why things sink or float
Whether an object sinks or floats depends on its density - how heavy it is for its size - compared with water. Objects that are less dense than water float on top, while objects that are denser sink to the bottom. Kids can test lots of objects here and discover the pattern.
Predicting like a scientist
Real scientists make a guess, called a hypothesis, before they test something. This game builds that habit: first predict whether the object will sink or float, then drop it and observe what really happens. Guessing and checking is how we learn.
Frequently asked questions
Why do things sink or float?
An object floats if it is less dense than water and sinks if it is denser. Density means how much matter is packed into a space, so a small heavy object can sink while a big light object floats.
Does a heavy object always sink?
No. A huge steel ship is very heavy but still floats, because its shape spreads its weight over a lot of water and traps air inside. What matters is density, not weight alone.
Why does a big ship float?
A ship floats because it is hollow and full of air, which makes it less dense than water overall. It also pushes aside a lot of water, and that water pushes back up and holds the ship afloat.