State Of Matter

Solids are usually hard, because their molecules have been packed together. Solids can be hard, soft, big or small like grains of sand. The key is that the solids hold their shape and they don't flow like a liquid. A rock will always look like a rock unless something happens to it. The same goes for a diamond. Even when you grind up a solid into a powder, you will see tiny pieces of that solid under a microscope.

 

Liquid

They can be found between the solid and gas states. They don't have to be made up of the same molecules. If you have a variety of materials dissolved in a liquid, it is called a solution. One characteristic of a liquid is that it will fill up the shape of a container. Another trait of a liquid is that it is difficult to compress. When you compress something, you measure out a certain amount of material and force it into a smaller space. Water is a liquid.

Gas is everywhere. There is something called the atmosphere. That's a big layer of gas that surrounds the Earth. Gases are random groups of atoms. Gases are really spread out and the atoms and molecules are full of energy. They are bouncing around constantly.

Plasmas are a lot like gases, but the atoms are different, because they are made up of free electrons and ions of an element such as neon (Ne). You don't find naturally occurring plasmas too often when you walk around. They aren't things that happen regularly on Earth. If you have ever heard of the Northern Lights or ball lightning, you might know that those are types of plasmas. Plasma is different from a gas, because it is made up of groups of positively and negatively charged particles. In neon gas, the electrons are all bound to the nucleus. In neon plasma, the electrons are free to move around the system.