Example of a Substance in the Solid State: Ice
Ice is a common example of a substance in the solid state. When water is cooled below its freezing point of 0 degrees Celsius, it undergoes a phase change from a liquid to a solid, forming ice.

Structure of Ice:
Ice is made up of water molecules arranged in a crystalline structure. In the solid state, these molecules are held together by hydrogen bonds, which are strong intermolecular forces that give ice its rigid and ordered structure.

Physical Properties of Ice:
- Ice is transparent, with a slightly bluish tint.
- It has a fixed shape and volume, maintaining its structure until it melts.
- It is less dense than liquid water, which is why ice floats on water.
- Ice has a melting point of 0 degrees Celsius and a boiling point of 100 degrees Celsius at standard atmospheric pressure.

Uses of Ice:
- Ice is commonly used for preserving food and beverages.
- It is also used in cooling systems, such as refrigerators and air conditioners.
- Ice is used in various recreational activities, such as ice skating and ice hockey.
Overall, ice serves as a prime example of a substance in the solid state, exhibiting specific physical properties and structures that distinguish it from liquids and gases.