What are the three common states of matter?

The three common states of matter are solid, liquid, and gas. This classification is essential in understanding how materials behave under varying temperature and pressure conditions.

In a solid state, particles are tightly packed together, leading to a definite shape and volume. The intermolecular forces are strong, allowing solids to maintain their form. For liquids, the particles are still close but can move past each other, providing a definite volume while taking the shape of their container. In the gaseous state, particles are far apart and move freely, resulting in neither a definite shape nor volume, allowing gases to expand to fill any space available.

Understanding these states is foundational in fields like HVAC and refrigeration, as they relate directly to the behavior of refrigerants and the principles of heat transfer and phase changes, such as condensation and evaporation.