Chapter 12 · Liquids, Solids, and Intermolecular Forces
12.2Properties of Liquids and Solids
8 min · two checks
Predict
Which is denser for almost every substance, the solid or the liquid — and what is the famous exception?
The idea
- Compare compressibility, shape, and density of liquids and solids.
- Note water’s density exception.
Liquids and solids are condensed phases: particles are touching. Neither is very compressible. Solids keep their shape; liquids flow. Diffusion is slower than in gases because a particle must jostle past neighbors rather than fly across empty space. Density is higher than in the gas, often by a factor near a thousand.
Most solids sink in their own liquids. Water does the opposite near the freezing point because ice’s structure holds molecules farther apart, on average, than the liquid does. That single exception matters for lakes, rocks splitting as ice forms, and the fact that you are looking at floating ice rather than a frozen-from-the-bottom ocean. Do not generalize it to every substance.
Keep these
- Condensed phases are nearly incompressible.
- Solids are usually denser than their liquids.
- Ice is less dense than liquid water.