Explanation:
Glass is a unique substance that displays both solid-like and liquid-like properties. It is not a typical solid because it lacks a crystalline structure, but it is also not a typical liquid because it does not flow like one. Instead, glass is classified as a supercooled liquid, which means it is a solid that has been cooled so quickly that it has not had time to form a crystalline structure.

Supercooled liquid:
A supercooled liquid is a substance that is cooled below its freezing point, but it remains a liquid because there are no nucleation sites for the formation of crystals. Glass is a supercooled liquid because it has cooled so quickly that the molecules have not had time to arrange themselves in a crystalline structure. Instead, they are randomly arranged like a liquid, but they are frozen in place like a solid.

Properties of glass:
Glass has several unique properties that make it different from other materials, including:

1. Transparency: Glass is transparent, which means that light can pass through it. This property makes it useful for windows, lenses, and other applications where transparency is important.

2. Brittleness: Glass is brittle, which means that it is prone to shattering when subjected to stress. This property makes it less desirable for certain applications, such as building materials.

3. Resistance to chemical attack: Glass is resistant to most chemical attack, which means that it can be used to store and transport chemicals without reacting with them.

4. Thermal expansion: Glass has a low coefficient of thermal expansion, which means that it does not expand or contract much when subjected to changes in temperature.

Conclusion:
In conclusion, glass is not a typical solid or liquid. Instead, it is classified as a supercooled liquid because it has properties of both solids and liquids. Its unique properties make it useful for a wide range of applications, including windows, lenses, and chemical storage.