MATTER IS ANYTHING THAT HAS A MASS. It includes everything from natural substances, such as minerals or living organisms, to synthetic materials. Matter can exist in three distinct states—
solid, liquid, and gas. A solid is rigid and retains its shape. A liquid is fluid, has a definite volume, and will take the shape of its container. A gas (also fluid) fills a space, so its volume will be the same as the volume of its container. Most substances can exist as a solid, a liquid, or a gas: the state is determined by temperature. At very high temperatures, matter becomes plasma, often considered to be a fourth state of matter. All matter is composed of microscopic particles, such as atoms and molecules. The arrangement and interactions of these particles give a substance its physical and chemical properties, by which matter can be identified. There is a huge variety of matter because particles can arrange themselves in countless ways, in one substance or by mixing with others.Natural glass, for example, seems to be a solid but is, in fact, a supercool liquid: the atoms are not locked into a pattern and can flow. Pure substances known as elements combine to form compounds or mixtures.
Mixtures called colloids are made up of larger particles of matter suspended in a solid, liquid, or gas, while a solution is one substance dissolved in another.
