Solid (state of matter)

A solid is one of the main states of matter. Solids are made up of atoms or molecules that only move within a very small range in relation to one another.

Solids at their respective melting points change to liquids. Solids can vaporize directly into a gas in a process called sublimation. Examples of this are dry ice becoming carbon dioxide gas, and ice disappearing without melting.

Some of the properties of a solid are Young's modulus, which is a measure of how a solid responds to deformation, hardness, which is a measure of how a solid resists abrasion, and melting point, which is the temperature at which a solid becomes a liquid.

A crystalline solid has atoms or molecules arranged in a regular repeated pattern and may abruptly change phase as the temperature changes.

An amorphous solid is an apparently solid substance that does not abruptly change its phase as its temperature changes. The atoms or molecules in it are arranged randomly.

Solid measures

Quantities of liquids are measured in units of volume, such as the cubic meter (m³), and mass, such as the kilogram (kg).