106 Plasma: The Fourth State-Mid

Plasma The Fourth State FOCUS Question How is plasma different from other states of matter?

Another State You eat solid foods every day. You drink liquid water, And you breathe air, which is a gas. Solids, liquids, and gases are states of matter. There is another state of— matter that you may not have heard of plasma? What is plasma Plasma is similar to gas. It has no specific shape. But plasma has more energy than gas. The particles that make up plasma each have an electrical charge. Some of the particles have a positive charge. Others have a negative charge. As a result, plasma can carry electricity.

From Gas to Plasma Plasma forms when a lot of energy is added to a gas. That energy can come from different sources. Electrical energy can change a gas to plasma. So can ultraviolet light or some laser light. Heat energy can also change a gas to plasma. Any of these sources can give a charge to the particles of a gas. This charge makes the particles move really fast. But matter cannot stay in the plasma state without an energy source. When the source is turned off or runs out, the plasma becomes a gas again.

Plasma in the Atmosphere Lightning is a kind of plasma. During thunderstorms, negative charges build up at the bottom of clouds. They are drawn to positive charges in the ground. When the pull is strong enough, the negative charges move. They quickly go from the cloud to the ground. The gases in the air are changed into plasma. The plasma gives off the light we see. The northern and southern lights are called auroras They are another kind of plasma. Particles from the Sun reach Earth's poles. These particles collide with particles in the air and create energy. The light we see is plasma.

Plasma in Space Plasma is more common in outer space than on Earth. All the stars you see in the night sky are made of plasma. That means our Sun is also made of plasma. Much of the material between stars is also plasma. If you look closely at a picture of a comet, you'll see two tails. One of the tails is dust made of rock and ice. The other tail is plasma. Ultraviolet light from the Sun adds energy to gas molecules and charges them. This creates the glowing plasma tail. Wowser! Plasma makes up 99 percent of what we can see in the universe. This includes stars, nebulae and galaxies.

Plasma in Lights Back here on Earth people use plasma in several ways. Do you use fluorescent lights in your home? Have you seen a colorful neon sign? These two types of lightbulbs have gases inside them. The gases change to plasma when energy is added. Inside both kinds of bulbs, electricity gives the gas particles a charge. The particles start to zoom around in the tube. As the particles bump into one another, they give off light. The entire bulb glows.