Back in early grade school, we were taught that there were three states of matter. Solids are substances whose atoms are packed tight enough and moving slow enough that the molecule retains its same shape and same volume. Liquids are substances whose atoms are loose enough and moving fast enough that the atoms can slide over one another and move freely in order to take on the shape of the container it is in, yet keep its same volume. Gases are substances whose atoms are moving very quickly and are almost free from the molecule. This is why gases can take the shape of the container they’re in and change their volume to fit the container as well. However, if you continued your education to middle school, you were taught that there was one more state of matter. This state was known as plasma.
Plasma is the state of matter where the substance’s atoms gain enough energy from the heat it absorbs that the electron bonds of the atoms break apart, therefore ionizing the gas. Plasma is very similar to gas because it takes on the shape and volume of the container it is in. The reason plasma is a distinct state of matter is because plasma responds strongly to electromagnetic fields, which makes it very different from solids, liquids, and even gasses.
Plasma was first identified in a Crookes tube by Sir William Crookes. Crookes called it “Radiant Matter”, and it wasn’t until 49 years later that it was dubbed “Plasma” by Irving Langmuir. Several examples of plasma you can see often are lightening, welders, neon signs, and even some fires. A very good example of plasma that can easily be seen is in a plasma lamp. The colors in the lamp are caused by plasma electrons to “relax” and then become excited again.
True, a 4th grader might tell you that there are three states of matter, and in some ways, he is right. Plasma isn’t much different from gas, but it is different enough that it deserves to be considered its own state of matter. It’s just like if someone said apples and oranges were the same. Apples and oranges may be very similar, but they are too very different fruits and are not the same. Any good scientist would tell you, hands down, there are four distinct states of matter. It’s time we think of it that way.
