Activity Overview
Gather a whole bunch of common objects from around your home or yard and perform the Float or Sink Experiment with your little ones. In this experiment, children can make predictions about whether or not an item will sink or float when placed into water.
When an object sinks, it goes down with gravity, and when an object floats, it can stay up by itself. Weight is one factor in sinking and floating, but it is not the cause. This experiment demonstrates how items of different densities will float or sink. Young children may not be ready to understand why objects sink and why they float, but they can make hypotheses and observe what happens when they are dropped into water.
Some children may think an object sinks or floats because an object is heavy or light. But not all heavy objects sink, and not all light objects float. For example, large ships are very heavy but they float. Also, a pound of feathers will float and a pound of bricks will sink.
Materials Needed
- Various common objects from around the house
- A bucket of water
How to Do It
- Fill bucket up with water.
- Collect a variety of objects that sink and float. Make sure to collect objects that have another object that is similar in size but vastly different in density.
- Ask your child to predict whether the object will sink or float and let them drop it in the water.
- Drop each item into the water and watch what happens.
- Have your child classify them into two different piles, items that float and items that sink to the bottom.
