plasma?

[nagendraelex]

how you explain plasma exactly??

[insane_alien]

ionized gas.

 

unless you're talking about biological plasma then all i know is that it is a part of blood.

[dirtyamerica]

+1, what insane_alien said.

 

the gas becomes so energetic that the atoms cannot keep a hold of all their electrons

 

so they fly off or become shared randomly with other atoms (I'm don't remember).

[Sisyphus]

What this means in practical terms is that it's just gas that can conduct electricity. What sort of explanation did you have in mind?

[DJBruce]

Although it is created by ionizing gas it is important to remember that it is a separate phase.

[dirtyamerica]

it is important to remember that it is a separate phase.

 

 

agreed.

 

but explaining it based on well-known concepts helps:D

 

EDIT: I just thought of this but is there any latent heat required for plasma formation? I've never heard of this before.

Edited July 17, 2008 by dirtyamerica

[nagendraelex]

thanks for reply..

im agreed that the conductive stage of gas is plasma ,this is fourth state of matter. it forms very high energy by diffusion of atoms.

[Sisyphus]

Although it is created by ionizing gas it is important to remember that it is a separate phase.

 

 

EDIT: I just thought of this but is there any latent heat required for plasma formation? I've never heard of this before.

 

Sort of. There is a certain, fixed amount of energy needed to break off an electron, called the ionization potential. However, it doesn't really work the same way as latent heat in melting and boiling, since it doesn't happen at a fixed temperature. In fact, the line between normal gas and plasma is quite fuzzy, since a) almost any gas is going to have some ions, b) the transition is gradual as temperature increases, and doesn't happen all at once, and c) a gas will behave like a plasma even if only about 1% of its atoms are ionized. Thus, it's not totally incorrect to think of it as a quality of hot gas rather than a separate phase. Calling it a separate phase is the convention, but that's mostly arbitrary compared to the differences between solids, liquids, and gases.

[likewhat]

Since the energy distribution of the particles in any system that is in thermal equilibrium will be maxwellian you have some high energy particles in the tail of the distribution. As you raise the temperature of a gas eventually the high energy tail will have sufficent energy to ionize gas particles. Actually this is always happening howver the recombination rate is much higher than the ionization rate at room temperature. At high temperatures you have more ionization and you can get a large amount of you gas ionized.

 

Ok so now you have an ionized gas, so what? Well, since it is ionized there are free electrons. These can be quite easily moved with an electric field( F=ma=e*Efield). So the conductivity of a plasma is extremely high. The particles can also be influenced by magnetic fields (F=ma=ev x B).

 

There are many uses of plasmas, they are used for making semiconductors, lighting, fusion, waste disposal, microwave/light production, etc..

 

hopefully that is enough to get you started

[nagendraelex]

thanks for your kind rely..

its a gud definationas i need.

[krash661]

something interesting,

 

Understanding the turbulence in plasmas

New experiments in a tokamak fusion reactor reveal details of a cooling process, potentially bringing practical fusion closer.

 

http://web.mit.edu/newsoffice/2013/understanding-turbulence-in-plasmas-0429.html

[PureGenius]

It usually travels in a type of cloud ball formation at high to medium velocities 600 800 kilometers per second in the case coronal mass ejections originating from sunspots. They will hold onto thier formation and when they strike earths magnetic field sometimes cause huge electromagnetic disturbances on earth, one was so powerful it fried telegraph wires all the way across the u.s.. These are actually clouds of plasma supercharged by a magnetic twist on the surface of the sun if one of these clouds.were to directly strike say a small space vessel it would most likely fry its electrical circuits instantly .

Edited April 30, 2013 by PureGenius

[John Cuthber]

It usually travels in a type of cloud ball formation at high to medium velocities 600 800 kilometers per second in the case coronal mass ejections originating from sunspots. They will hold onto thier formation and when they strike earths magnetic field sometimes cause huge electromagnetic disturbances on earth, one was so powerful it fried telegraph wires all the way across the u.s.. These are actually clouds of plasma supercharged by a magnetic twist on the surface of the sun if one of these clouds.were to directly strike say a small space vessel it would most likely fry its electrical circuits instantly .

Or it could be a candle flame.

[PureGenius]

Oh ok so fire is a plasma state ?

 

Because a candle has no electical charge nor the ability to maintain spacial integrity while moving at high velocitys ?

Edited April 30, 2013 by PureGenius

[swansont]

Oh ok so fire is a plasma state ?

 

Because a candle has no electical charge nor the ability to maintain spacial integrity while moving at high velocitys ?

 

Coronal mass ejections are all plasmas, but not all plasmas are coronal mass ejections.

[imatfaal]

http://www.realclearscience.com/video/2012/09/18/flames_theyre_electric.html

 

Great demo

[krash661]

great video..

 

it appears electricity is a big part of everything,

but then i'm lead to electric universe idea when ever i think about this thought.

[John Cuthber]

What I'd like to know is why people thing plasma is a different state of matter?

The air we are breathing is ionised - not much- but there are certainly ions produced by cosmic rays etc. Anyone who has seen a cloud chamber can verify this.

No gas is ever entirely ionised.

So, where on the scale from totally not ionised (which we never see) to totally ionised( which we also never see) does it magically convert from one state of matter to another?

[swansont]

It counts as a different state because some behaviors are very different, just as with the transitions between other states.

 

But is doesn't involve discontinuities, so you have to pick a point. However, this is not unprecedented. When does a glass transition change from liquid to solid?

[John Cuthber]

OK, does ordinary air behave very differently from, for example, the air at the bottom of a deep salt mine where the ionisation is less due to screening from cosmic radiation.

For glasses the typical "transition" is where the viscosity reaches 10^12 poise (IIRC- but it's some arbitrary number)

How ionised does a gas have to be before it's counted as a plasma?

[swansont]

OK, does ordinary air behave very differently from, for example, the air at the bottom of a deep salt mine where the ionisation is less due to screening from cosmic radiation.

For glasses the typical "transition" is where the viscosity reaches 10^12 poise (IIRC- but it's some arbitrary number)

How ionised does a gas have to be before it's counted as a plasma?

 

Depends on the measurement criteria, much like with a glass transition — there's more than one, and the transition temperatures often only roughly agree. What does the light transmission curve look like, for one example? Or, what is the electric field, and the conductivity?

[John Cuthber]

To be fair, the 3 normal "states of matter" have the same issues. Supercritical fluids and things like silly putty rather mess with the definitions.