Ice floats in water because it is less dense than water. The density of ice is 0.917 g/cm^3, while the density of water is 1.000 g/cm^3. This means that ice is about 9% less dense than water.

The reason why ice is less dense than water is because of the way water molecules are arranged in ice. In liquid water, the water molecules are constantly moving and colliding with each other. This causes them to spread out and take up more space. However, in ice, the water molecules are arranged in a more orderly pattern. This pattern leaves less space between the molecules, making ice denser than liquid water.

When ice is placed in water, it displaces an equal volume of water. However, the mass of the ice is less than the mass of the water that it displaces. This means that the ice will float on top of the water.

The fact that ice floats in water is important for many reasons. It helps to protect aquatic life from freezing, and it also helps to regulate the Earth’s climate.

Here is a simple experiment you can do to see for yourself why ice floats in water.

1. Fill a glass with water.
2. Add a few ice cubes to the glass.
3. Observe that the ice cubes float on top of the water.

This experiment shows that ice is less dense than water. The ice cubes displace an equal volume of water, but the mass of the ice cubes is less than the mass of the water that they displace. This is why the ice cubes float on top of the water.