plasma-the 4th state of matter

I couldn’t understand what is meant by Plasma?
And what one means by fourth state of matter?

Short answer, may not mesh with some newer theories: Plasma is a state of matter in which electrons are separated from the nuclei of the atoms. It has unique properties, including a propensity for nuclei to fuse together and make heavier elements (with a large amount of energy released), that make it distinct from other states of matter. I can explain more, but I must admit beforehand that my understanding of physics is hopelessly trapped in the 1980s and the books on the subject I read then (mostly Asimov nonfiction).

Think of plasma as being an extremely energetic gaseous phase.

What they said. Also by the fourth state of matter they mean that there are four states any matter can be in:

solid (ice - molecules are arranges in a lattice)
liquid (water - molecules still interact, but can align more freely)
gas (steam - molecules interact weakly)
plasma (electrons and nuclei are seperated

Basicly (aka not always the case) you get from a lower state to a higher by raising the temperature/pressure.

Example:
Below 0 degrees celcius water is in it’s solid state, between 0 and 100 degrees celcius it’s liquid, above 100 it’s steam and way up higher (we’re talking temperatures that are several thousand kelvin) it’s in the plasma state.

Hope it helps.
Tikster

Actually plasma is the normal state of matter. On a universal level, the overwhelming majority of matter exists in a plasma state. It’s only under local conditions that a relatively small amount of matter forms into a non-plasma state.

Yes, well…

The matter in working stars is in a plasmic state, and stars contain lots of mass.

Then again, there’s alot of cold dust and gas floating around between solar systems, at a very low density mind you, but it adds up despite itself.

And then there’s that dark matter that keeps coming up on a regular basis, and phase hasn’t been discussed regarding that stuff.

I’m not sure what the ratio of stellar-plasmic-stuff to cosmic-void-gas/rock-stuff is exactly…

I’ve read that over 99% of the matter in the universe is in a plasma state. Admittedly, I don’t have a cite handy and it’s 4:00 am so I’m not going to start looking for one now.

Well if you want to discuss cosmology, that’s a whole 'nother ballgame :slight_smile:

I think the question was about the matter we do know something about (about 4% of the total mass in the universe* - scary isn’t it). It can quickly become more complicated.

A (less educated)** guess would be that about one fifth*** of a stars’ mass is in the plasma state - and most of the matter in the universe is in stars/black holes… So about the same proportion of known matter would be in this state.

Dark matter: We simply don’t know enough to make even an uneducated guess***.

Some even include a fifth state of matter****: the bose-einstein condensate. Nevermind that not all elements can enter this phase - to my mind, it’s a little artificial to lump it in with the other four states. Plus - given the low (microkelvin) temperatures involved - how much matter is in this state outside physics labs across the world…

-Tikster (Whose knowledge in this area seems to have dropped drastically - heeeeeeelp).

*Cite:regular matter is 4% of the total closure density in the universe .
** I’ve only attended one astronomy class.
*** Your guess is as good as mine.
****Cite:bose-einstein condensates included in states of matter

If you search on “exotic states of matter”, you can find all kinds of interesting things. At least one author considers liquid crystals, superfluids and superconductors to be distinct states of matter. So we’re up to eight now, and that’s not including any of the really weird stuff (Bose-Einstein is normal) that can occur in quantum systems.

What’s the state of a single molecule of something in complete isolation?

Lonesome.

There are actually 6 states of matter. Bose-einstein is what happens when particles reach almost absolute zero (absolute zero is the lowest possible temperature, about -273 C below zero)

http://jilawww.colorado.edu/www/press/bose-ein.html

Filament is another state that occurs when temperatures reach extremely high temps (above that which plasmas are formed)

http://www.5th-state-of-matter.info/5th-state.html

I am not sure what they mean or what defines them though. But there is a nice chart there.

It doesn’t have one. The state of matter is a property of a (large) group of molecules.

That’s not quite right. The state of matter (or phase) is a property of the interactions among molecules. Since there are no such interactions if you only have one molecule, you can’t really assign a phase to it.

HAH! :smiley:

Take a fluid that is otherwise a gas and shake it so hard that the collisions break electron-bonds and states during every collision. Thus, you get a state where the electrons act as if they are in a bulk state over many atoms, and the nuclei are not bound directly.

The properties are very cool and are still being explored [ try Plasma Physics Experiment ].

Of course, for higher temperature plasmas (I think someone said it already), the particles bang so hard together that nuclear bonds are broken with each collision – resulting in a bulk nuclear mixing state. I almost wish that there would be a concensus to separate plasmas into two smaller states – one dealing with free nuclei/electron separation and one dealing with nuclei separation. If anyone has heard of this, shoot away.

One distinguishing feature of plasma is the high electrical conductivity. Electrons and nuclei are moving independently and flow freely. Unlike gas, plasma interacts strongly with elextric fields and magnetic fields.

I would argue that a single molecule somewhere is in the gaseous state. It doesn’t have covalent/ionic/hydrogen/etc. bonds that would make it solid or liquid, and it’s got electrons. Therefore, gaseous. A very diffuse gas.

Can’t we measure the energy of a single molecule without respect to other nearby molecules? In which case would could describe what state it would be in prior to measurement if it were indeed near other molecules.

It’s actually a lot easier to define a state change than it is to define the states themselves. If you add energy to a system, and it doesn’t increase in temperature but does something else instead, then it’s going through a state change. For instance, if I have a 1 gram piece of ice at -40 Celsius, and add 1 calorie of energy to it, it’ll heat up to -39 Celsius. If I add another calorie, it’ll heat up to -38 Celsius, and so on. When it gets to -1 Celsius, I add another calorie: Now it’s at 0 Celsius. If I add another calorie, it’s still at 0 Celsius, but a little of it has melted. About 80 more calories later, it’ll all have melted, but still be at 0 Celsius. Now, if I add another calorie, it’ll finally hit 1 Celsius. I added 80 calories of heat without it changing temperature at all, so it must have been doing something else (namely, melting). So we say that melting is a state change, and therefore that ice and liquid water are different states.

But, of course, it’s more complicated than that. One can, for instance, have a state change where the “before” and “after” states are both what we would call solids. They might have different crystalline structures, for instance. In fact, if you have cold enough temperatures and high enough pressures, water ice itself has 8 or 9 different states. Many other substances have multiple solid states (and possibly multiple liquid or gas states, too, though I don’t know of any examples), but they won’t necessarily correspond to the states of ice. So “solid” isn’t really one state, but millions of them, with different ones for each substance.