Stages of Matter

The stages of matter refer to the physical forms substances can take: solid, liquid, gas, and plasma. Solids have fixed shapes and volumes because their particles are tightly packed. Liquids have fixed volume but can flow and change shape, as their particles are less tightly bound. Gases have no fixed shape or volume; particles move freely and spread out. Plasma, a high-energy state, consists of ionized particles and is found in stars and some specialized conditions. Transitions between these states occur with changes in temperature or pressure, reflecting how particles gain or lose energy and move relative to each other.