Here's why:

* Density: Density is a measure of how much mass is packed into a given volume. Water has a density of 1 gram per cubic centimeter (g/cm³).

* Buoyancy: When an object is submerged in water, it experiences an upward force called buoyancy. This force is equal to the weight of the water displaced by the object.

* Floating: If an object is less dense than water, it means it has less mass packed into the same volume. This allows it to displace enough water to create a buoyant force equal to its own weight, causing it to float.

Let me know if you have any other questions!