# Tag Info

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Since you're talking about thermal physics, it's probably worth talking about this purely in a thermal context. What does it mean for something to have a high amount of energy? It means that we can do a lot of work with it. So let's say we have some sort of machine that uses something to do work as efficiently as possible. Since we're talking about solids ...

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Combustion is a chemical reaction where the molecules rearrange themselves and is VERY VERY different from change of phase. The energy stored in the solid phase is not necessarily more than that stored in the liquid phase. For example, it takes more energy to convert water into stream ($2260 KJ/kg$) than ice into water ($334 KJ/Kg$).

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In the old days, most plasmas were created with discharges in gases or such. This can stay a plasma for a long time (at least seconds). If it were not quasi-neutral, the accumulated charge would strongly pull ions away from electrons and make the plasmas explode. That's why books make this claim, and it is still true in many cases. Nowadays, plasmas can be ...

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I will give you mathematical background that explains where sound waves, as well as shear, and other waves come from in continuum approximations and why viscosity has no influence on such waves: In Eulerian form, the vector equations of motion for a fluid or solid continuum can be written as \frac{\partial \mathbf{q}}{\partial t} + ...

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A "new" state of matter comes into being, when one (or more) scientist discovers it and "enough" other scientists agree/accept, that it IS!

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With solids atoms are mostly locked in place so it makes sense there can be lots of different crystal structures and atomic packings. For liquids and gases though their defining characteristic is that their atoms are mobile enough to flow and fill a container. You can't both have structure and mobility.

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In a plasma it is hard to specify the state as solid, liquid, or gas but a good way to think about it is to ask what is driving the interactions in the plasma. Literature often cites the plasma coupling parameter $\Gamma=Z^2 e^2/(k_b T a)$ where a is proportional to $(number \ density)^{-1/3}$, T is the temperature, and Z is the charge number. This can ...

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Substances in solution have the effect of decreasing the temperature of the freezing point of the liquid they are dissolved in. This is called freezing-point depression. This is one of the reasons why adding salt to ice helps it melt. Your coke is a complicated solution + colloid and sugar is one of the main substances dissolved in it. During freezing: ...

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Have you ever looked at a peanut and said, "gee, what an interesting liquid"? Most people would answer in the negative. Peanuts are about 25% liquid fat by weight, but the liquid is held together in a solid form by the proteins and carbohydrate solid matrix which comprises the body of the nut. When this solid matrix is fragmented by mechanical grinding, ...

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