Handbook 752 Air Conditioning and Climate Control Temperature Determines State The concept of heat is directly related to the nature of all materials. Some materials are solid, some are liquid, and some are gaseous. In fact, all matter can exist in each of these three states depending on its temperature. Using water (H 2 0) as an example, we can commonly find water in any of three states: ice, water and steam. Its temperature is what determines the state of water. Three States of Matter Matter has different characteristics as it exists in each different state. For example: 1. A solid has a defined shape and cannot flow to fill empty spaces in a container. 2.
A liquid can flow to fill voids in a space, but it cannot be compressed or made more dense by pressure. 3. A gas (or vapor) also flows easily, and it can be compressed; that is, its density can be made greater or smaller by applying pressure to a closed vessel containing the gas. As heat energy is applied to a solid, the solid absorbs the heat (we could say it gets hotter) up to a point. If the solid is heated past its freezing point, it will gradually become a liquid. In fact, this relationship is consistent for each material. However, the process of changing its state requires the addition of an extra amount of heat. 16 Technical Training