The three states of matter... or four ?

[Masquerouge]

It's amazing how things you took for granted can be simply blown away.
So I've always heard about the three states, solid, liquid and gas, and thought it a decent theory

But today, I realized something. I could find weird states that I'm not sure about. Like sand. Or foam. Or paste. Or magma.
So to what exactly do the three states apply to ? Must it be a pure body, like pure hydrogen, pure Sodium ? Apparently not because water has these three states.
So if molecules are ok, then can they be as big and complex as we want ? Because clearly foam (say your shaving foam) is made of complex molecules.
Or is foam actually a liquid ? But then what defines a liquid ?

So I guess my metaphysical interrogations are :
What precisely defines a solid, a liquid, a gas ?
To what do these states apply ? Pure elements, molecules...

 

[Elta]

I din't learn till High School but Plasma (not the blood plasma but rather the stuff in the sun) is indeed the 4th element
..It's logical to skip that in grammer school I suppose (Iam not saying or assuming that your in grammer school )

The same with negative numbers.

 

[Abaddon]

Love is the 5th element...

 

[Perfection]

There are lots of states of matter, we just deal with 3 on a common basis.
http://en.wikipedia.org/wiki/Phase_(matter)

 

[History_Buff]

There are in fact 5 states of matter we know of, and there may be even more at higher energy levels.

Plasma, Gas, Liquid, Solid, and Bose-Einstein condensate. (And there are apparently other more complicated ones as well according to that Wiki article, I thought the others were just substrates to Plasma and BE condensates.)

Sand is a solid, just like salt, there are just thousands of crystalls which give it the illusion of liquidity. Foam is a plastic, and I'd classify it as a highly malleable (bendy) solid, like a hot metal. It expands because there is gas inside of it, trying to expand and escape. Paste out of the bottle is a liquid, might react with the air to become a solid. Magma is the easiest of the lot to classify, it's just metal that has been heated until it melted into a liquid.

Your 5 states of matter apply to anything that has mass. Defining them is tricky in day to day terms though. Generally, if it holds it's form under pressure, and does not flow, it is a liquid. If you can pour it, it is a liquid. Anything else is a gas. And that really is the best generalization I can come up with.


One of the most interesting cases in the state of matter discussion though is probably glass, which is in fact a liquid. It's viscosity is just so high that it takes years for it to go anywhere. If you want to see it for yourself, goto a really old building (50+ years old) and look at the windows. You will see everything clearly through the top part of the window, but looking though the bottom will give a distorted image, because it is so much thicker and rounder than the top.

There are also 11 different types of Ice, all with unique properties and appearances on the microscopic scale.

And thank you to SomethingWitty, non-newtonian fluid is the term that applies to things like plastics, slurries, etc.

 

[SomethingWitty]

The usual textbooks give four states of matter- gas, liquid, solid, and plasma.

There are unusual substances- sand, pastes, ketchup, etc. that fall under categories such as "non-newtonian fluids" and other such things.

A gas is a substance with low density and viscosity, which expands to completely fill its container.

Liquids are substances that flow but are essentially non-compressible.

Solids are substances with a definite shape and volume, that doesn't flow.

At STP, hydrogen's a gas, sodium's a solid, and water's a liquid.

Solids, liquids, and gases can apply to any substance. Seawater is a liquid even though it's a complex mixture.

 

[Mise]

But today, I realized something. I could find weird states that I'm not sure about. Like sand. Or foam. Or paste. Or magma.

Sand is a solid, "foam" is a liquid with gas inside it (to make it "foamy" - I assume you mean like shaving foam), paste is a liquid, magma is a liquid.

water has these three states.

Water is a liquid, ice is a solid, steam is a gas. All are H2O.

 

[The Last Conformist]

You also get stuff like degenerate matter, and it's evil older brother neutronium.

 

[nonconformist]

Not all substances have the same number of states.
It's somewhat random, though I expect there's a orbital explaination of it.
Carbon Dioxide, for example, exists as a gas, or a solid, but never a liquid.

 

[The Last Conformist]

Same for pure carbon, incidentally.

 

[nonconformist]

I was actually unsure for that matter.

Plasma is an interesting substance-crated through total ionisation, where the electons completely seperate from the nuclei.

 

[SomethingWitty]

Not all substances have the same number of states.
It's somewhat random, though I expect there's a orbital explaination of it.
Carbon Dioxide, for example, exists as a gas, or a solid, but never a liquid.

You can have liquid carbon dioxide, just not at standard pressure.

You can also have liquid carbon, just not in the presence of oxygen.

 

[The Last Conformist]

You can also have liquid carbon, just not in the presence of oxygen.

Hm? If so, my chemistry textbooks lied to me.

 

[SomethingWitty]

Hm? If so, my chemistry textbooks lied to me.

What did your chemistry text book say exactly?

 

[Masquerouge]

Sand is a solid, "foam" is a liquid with gas inside it (to make it "foamy" - I assume you mean like shaving foam), paste is a liquid, magma is a liquid.

That's exactly what my question is. How do you know foam is a liquid ? What definition of liquid are you using ? Same for paste...

EDIT : the wiki article that Perfection linked to is pretty vague on the subject, too. What is the exact definition of a liquid, a solid and a gas ? And does it apply to any type of matter ?

Water is a liquid, ice is a solid, steam is a gas. All are H2O.

Yeah, that I knew Reminds me of that Calvin and Hobbes gag, about putting a slice of bread in the toaster, getting a toast, and wondering where did the bread go

 

[Esckey]

You can have soild hydrogen, just need the right pressure and tempature. Just look at the core of Jupiter....or is that liquid hyrdogen?

 

[Masquerouge]

A gas is a substance with low density and viscosity, which expands to completely fill its container.

Liquids are substances that flow but are essentially non-compressible.

Solids are substances with a definite shape and volume, that doesn't flow.

That seems pretty vague to me. For instance, glass could be said to be a liquid, because it does flow, only very slowly : very old glass, such as found in churches, is thicker at the bottom than at the top.
So at an instant T, glass could be said to be a solid, but over a very long time, it behaves like a liquid.

 

[SomethingWitty]

You can have soild hydrogen, just need the right pressure and tempature. Just look at the core of Jupiter....or is that liquid hyrdogen?

It's believed to have a solid metallic hydrogen core, yes.

Conditions have been replicated in labs at exceedingly small scales and durations.

 

[JohnRM]

It's amazing how things you took for granted can be simply blown away.
So I've always heard about the three states, solid, liquid and gas, and thought it a decent theory

But today, I realized something. I could find weird states that I'm not sure about. Like sand. Or foam. Or paste. Or magma.
So to what exactly do the three states apply to ? Must it be a pure body, like pure hydrogen, pure Sodium ? Apparently not because water has these three states.
So if molecules are ok, then can they be as big and complex as we want ? Because clearly foam (say your shaving foam) is made of complex molecules.
Or is foam actually a liquid ? But then what defines a liquid ?

So I guess my metaphysical interrogations are :
What precisely defines a solid, a liquid, a gas ?
To what do these states apply ? Pure elements, molecules...

Sand is a solid.
(Shaving) Foam is a liquid.
Paste is a liquid.
Magma is a liquid.

 

[nonconformist]

I believe foam is actually an emulsion.

Solid hydrogen I don't think exists.