A plasma is like a gas, only the molecules are charged, just like your body is charged when you get shocked from static electricity. Some examples of plasmas are:

The stuff inside neon lights is neon-plasma
The stuff inside street lamps is either mercury-plasma or sodium-plasma
The stuff inside florescent lights is a plasma of some sort, I don't know
The sun is made of hydrogen-plasma
Lightning is a streak of air-plasma
A flame is a plasma made of oxygen and the stuff you are burning
(Strangely enough, the Greeks considered fire to be a state of matter.)

Any gas you see that glows is probably a plasma.

PS there is another use for the word "plasma". Doctors refer to plasma as the liquid in your blood that the blood cells float around in. It is totally different stuff.

Sometimes it helps to think of plasmas as very, very hot gases.In some ways, a plasma is like a gas, but it is made up of charged particles. For examples you see everyday, just look up. If you are outside and it's daytime, you should see one - but you might not want to look directly at it. If you are in class, you might also see several. Ask your teacher what kind of light bulbs you have. In the lab where I work, we use special reactors in which we create plasmas (we electrically charge the gas in a steel chamber). Then we use the plasma to do chemical reactions.

Hope this helps!

You see it everyday of your life you can see the sun!!!
of course the sun is 1 AU from the sun where AU is the astronomical Unit ,1.5x10^11 m (93 million miles).

A plasma is an electrically conducting high temperature-- at high temperatures the electrons in outer shells can get "kicked out"...we say the gas is ionized...that is it has a charge.this state of matter applies at very high temperatures and low pressures. plasmas resopnd to electric and magnetic fields.

Temperature is really just the random, jostling motion of atoms. The hotter the matter, the faster the atoms move. With enough heat- 5000 degrees Centigrade is a good start- the atoms can collide so violently that they knock electrons off each other, overcoming the electrical attraction which binds electrons to nuclei. This process is called ionization. When that happens, you have a plasma: a soup of free-flying electrons, bare nuclei, and atoms with missing electrons.
Plasma obeys the ideal gas laws, assuming the temperature remains high enough to keep the electrons from settling down onto the atoms. However, because the electrons are free to move, a plasma conducts electricity just like metal. It also has some interesting magnetic properties that you wouldn't expect from an ordinary gas- for example, it can only flow along magnetic field lines, not perpendicular to them. If you forcibly move some plasma perpendicular to a magnetic field, the field moves with it- as if it were glued to the plasma!
You have seen plasma all the time without even knowing it. The Sun, the cores of lightning bolts, and blowtorch flames are all made of plasma. As for everyday uses- the blowtorch flame and the fluorescent bulb both contain weakly-ionized plasma. Some type of laptop computer screen uses glowing plasma in it's pixels. Our very thin upper atmosphere is made of plasma, and because of it's electrical conductivity, it reflects some types of radio signals just like a metal would. That's how ham radio operators can talk to each other despite the curvature of the Earth getting in the way. Also, they use plasma in the microchip factories for etching and planting small amounts of other elements into pure silicon wafers.

Actually you've seen plasma many times -- you just didn't recognize it. Plasma is a state of matter in which a large population of electrons and ions are "free" at any time. Have you ever looked at a neon sign up close? Inside, you have a thin gas of neon with a high voltage running through it-- in short a plasma. The sign is visible because there is a continuous process of electrons being captured by ions and then emitting light as the atom goes to its "rest" state. The atom is subsequently ionized again by scattering from another electron -- and the process repeats. In most plasmas there is a substantial amount of light and heat emission into the cooler areas surrounding it, as the internal ions and electrons recombine. There is even a more common place to see plasmas -- even the indians had ways of making and using plasmas -- can you guess what it was?

Plasmas are like gases (just like the other answerers said) but not quite. Maybe you know that atoms and molecules are made of electrons, which are negative charges, and nuclei (made of protons and neutrons), which are positive charges. In plasmas, some of the electrons are knocked off of the atoms, so plasmas are made up of some negative charges and some positive charges. Plasmas also behave in unusual ways because of the electrical forces between the negative and positive charges in them!

The first answer to this question gives lots of examples of where you find plasma, and the sun is a very good example because it is a big ball of plasma! Scientists are also very interested in plasmas because they can be used in nuclear fusion reactors, which might become a clean source of electrical power (maybe you can read about those reactors).

Here's a question: How hot do you think it would need to be for the atoms in a gas to lose their electrons and become a plasma? See if you can find out!

PS. The first answer says don't get this kind of plasma confused with blood plasma, because it is different. Biologists also call the stuff inside of our cells protoplasm or sometimes even plasma, and that is different, too!

Well, if you have ever seen a neon sign you have seen plasma. When you see a lightning bolt in the sky you have seen plasma.

Actually in both of these examples the plasma was created by the passage of electricity through a gas. The lightning is an electrical discharge through air and when it does so it ionizes the atoms, stripping the electrons from the atoms leaving positively charged ions in the gas. As the electrons which are negatively charged recombine with the ions they give off energy in the from of light.

The neon sign operates in the same way. A steady current flows through the gas, probably neon, and ionizes the atoms. As the electrons recombine with the gas ions they give off light and the pretty colors of the neon sign.

But the question I have for you is how do they get the "neon" sign to operate with different colors?

This is a very interesting question and I am happy to see that you are attempting to extend your understanding of the subject beyond a "textbook definition" by observing it in the world around you. As you know, plasmas are comprised of electrons, ions, and some neutral atoms. You may be surprised to hear this, but plasmas are actually the most common form of matter in the universe (at least for the visible part of the universe which we somewhat understand!). This may be surprising at first if you base your answer from your experience on earth, where solids, liquids, and gases are the
dominant forms of matter. But consider this - does the composition of the earth (and its states of matter) seem representative of the universe? To think about this question as a first approximation, try comparing the mass of the earth to the mass of the sun...

One thing to note about plasmas is the wide range of conditions over which they can exist. So to begin answering your question, let's first consider stars. The central core of a star is actually an extremely dense and hot plasma (now we begin to see why there is so much plasma in the universe!). Have you heard of the sun's corona (you can investigate that by studying total eclipses...) and solar winds? These are also plasmas, but much less dense and lower in temperature than the star's core. Have any of you been further north and observed the Aurora Borealis (Northern Lights)? There is an interesting relationship between solar winds and the "size" of the northern lights - what do you think auroras are?

So we can see how plasmas are very common when we think about cosmic scales. But what about every day experiences? Let me give you a couple of things to think about. When warm, moist air in the atmosphere rapidly rises, it can strip off some electrons to begin to build up a static charge. When enough charge builds up, the air can no longer sufficiently insulate and you get a sudden discharge (and a plasma) - do you know what I'm describing? A second example: I'm sure by now you have seen a fluorescent light bulb - but how do they work? It turns out that inside these lightbulbs there is a plasma. However, it is not actually the plasma that you see. The walls of the bulb are coated with a phosphor (you can tell if you look up close at one where parts of the coating have worn away). The plasma excites the phosphor to emit the white light that you see, but if the phosphor were not there, you would see the plasma (which would have a blue glow!). There are many other ways plasmas are used to make things that you use every day and I encourage to further investigate this subject!