Some interesting facts about water include the fact that it takes hot water less time to freeze than cold water, all conditions being equal. No one knows why this is, but some scientists believe it is an effect of convection.
Scientists also don't know why ice is slippery, even though they understand that there's usually a thin layer of liquid water on top of a body of ice. But scientists do not understand why this layer develops in the first place.
Molecules of water bond loosely, which allows for surface tension. Because of this, the molecules on the surface of a body of water are tugged downward. The surface water hangs together until something more powerful than the downward tug pulls them apart. This is why a material even denser than water floats on the surface.
The density of pure water is a bit less than 1 gram per cubic centimeter. Ice is less dense than liquid water, which is why icebergs float. The planet Saturn, a gas giant, is also less dense than water.
An adult's body is about 70 percent water. A newborn baby is about 80 percent water. The surface of the Earth is also mostly water, and most of the water that covered the Earth millions of years in the past still exists today.