Density involves the amount of a material in a certain volume. When a material changes phases, it changes in density in a predictable way as the amount of material stays the same but the molecules get farther apart or closer together. Water has solid and liquid states that do not follow these predictions of density in the phases of matter.

Question

What does that mean about the densities of the phases of water?

The solid state is the most dense, followed by the liquid state, then the gas state.
The solid state is more dense than the liquid state.
The liquid state is more dense than the solid state.
The gas state is the most dense, followed by the liquid state, then the solid state.

Answer 1

Water exhibits unique behavior in terms of its density across different phases. Typically, for most substances, the solid state is denser than the liquid state due to the molecules being packed tightly together. However, water is an exception to this general behavior.

In the specific case of water:

• The solid state (ice) is less dense than the liquid state (water). This is why ice floats on water.
• The gas state (water vapor) is the least dense compared to both the solid and liquid states.

Based on this information, the correct statement regarding the densities of the phases of water is:

The liquid state is more dense than the solid state.