States of Matter

I collect books of science experiments, and it amazes me how many still teach the three states of matter. I thought that this time, we would look at the FOUR states of matter. (Actually, there are more states of matter, but these four are the common ones.)

For this experiment, you will need:

  • an ice cube
  • a round glass
  • water
  • an ice cube tray
  • a neon indicator lamp (Ne-2 bulb)
  • a balloon

Most people are familiar with three states of matter: solid, liquid and gas. Things like rocks, wood and ice are solid. They stay the same size and shape, not matter what container we put them in. Place an ice cube into a round glass. It stays the same size and shape. It is solid..

Things such as alcohol, oil, and water are liquids. They stay the same size, but they change their shape to fit their container. Fill one of the holes in an ice cube tray with water. You now have a cube of water. Pour this into the round glass. The water stays the same size, but changes its shape to fit the glass. Water is liquid.

The most common gas, the air, is actually a mixture of several gases. Gases change their shape to fit their container, just as liquids do. They also change their size to fill their container. Can you imagine a container with a puddle of air in the bottom and the rest of it a vacuum? No, the air would expand to fill the container, at a lower pressure. Air is gas.

The fourth state of matter is called plasma. Do not confuse this plasma with the plasma in blood. That is something completely different. Plasma as a state of matter is similar to a gas. It changes it's size and shape to fit a container. The difference is that in a plasma, each of the atoms has lost its electrons. These free electrons are moving around between the atoms. For this reason, plasmas are good conductors of electricity. Plasma also gives off light, which make it easy to see.

To see some plasma, we will repeat a past experiment. The neon indicator bulb looks like a small light bulb until you look closely. There is not a filament or wire that lights up. Instead, the bulb is filled with neon gas at low pressure. All that we need to change this gas into plasma is some static electricity, which we can produce with a balloon. First, you will need a dark room. The darker it is, the easier it will be to see the plasma. Hold one of the wire from the neon bulb. Rub the balloon on your hair or a piece of cloth. This will build up a static charge on the balloon. Bring the balloon near the other wire of the neon bulb and you will see an orange flash in the bulb. This is neon plasma.

Some common examples of plasma are neon lights, fluorescent lights, lightning and other sparks. Plasma is found in flames. It is also what stars are made up of. When you consider that, you realize that most of the matter in the universe is plasma. In spite of the fact that most science books ignore plasma until you get to the college level, it is the fourth state of matter and by far the most common state in the universe.