The density of water has an inverse relationship with its boiling point. As the density of water increases, its boiling point decreases. This is because the denser the water, the more energy it takes to break the bonds between its molecules and turn it into a gas.

For example, at sea level, where the density of water is 1 gram per cubic centimeter, water boils at 100 degrees Celsius. However, at higher altitudes, where the density of water is lower, water boils at a lower temperature. For example, at the top of Mount Everest, where the density of water is about 0.7 grams per cubic centimeter, water boils at about 85 degrees Celsius.

This relationship between density and boiling point is not unique to water. It is true for all liquids. The denser the liquid, the higher its boiling point.