If an object is less dense than water, it will float. If it's more dense, it will sink.

Density is a measure of how much mass an object has for its size. The more mass an object has, the denser it is.

Wood is less dense than water. To be more specific, the density of wood is about 0.5 grams per cubic centimeter. Water, on the other hand, has a density of 1 gram per cubic centimeter.

So, because wood is less dense than water, it floats.

Here's a simple experiment you can do to illustrate this concept.

1. Get a piece of wood and a bowl of water.

2. Put the piece of wood in the bowl of water.

3. Observe what happens.

The piece of wood should float on the surface of the water.