What's the Matter?
States of Matter:
Everything around you is made of matter. Scientists group matter based on its properties, or characteristics: what it looks like and how it acts in different situations. Matter can take three different forms. The three forms are solid, liquid, and gas.
Solid matter has a definite shape. It also takes up a definite amount of space. Liquid matter takes the shape of its container. If you were to look at liquid matter under the microscope, you would see its tiny particles sliding past each other. In the form of a gas, matter is usually invisible. The air around us has several different gases, like the oxygen we breathe in and the carbon dioxide we breathe out.