The air you’re breathing. The chair you’re sitting in. The orange juice you may have had for breakfast. You. All these things have something in common. They are all examples of matter.
Most of the matter you see every day comes in one of three forms. It may be a solid, like grains of sand. It may be a liquid, like the water in the ocean. It may be a gas, like the air that helps keep a kite up. It may be a plasma, like what’s inside a fluorescent light. No matter how different these forms of matter seem to be, they are alike in some important ways.