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. The three forms are solid, liquid, and gas.
solid matter has a definite shape. It also takes up a definite amount of space. This means it has a specific volume. if you could look at solid matter under a very powerful microscope, you would see its tiny particles moving back and forth. The particles are packed together, so they vibrate in place. their overall shape does not change.