transitions between states of matter

Transitions between states of matter occur when energy—often heat—is added or removed, causing molecules to change their arrangement and behavior. For example, heating a solid increases molecular motion until it melts into a liquid. Further heating turns the liquid into a gas through vaporization. Conversely, cooling a gas condenses it into a liquid, and further cooling solidifies it. These phase changes involve breaking or forming intermolecular bonds and require or release energy. Overall, matter transitions between solid, liquid, and gas states due to changes in temperature and pressure affecting molecular interactions.