entropystates-of-matter
States of matter in physics are the distinct forms that different phases of matter take on. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma.
What is physics behind States of matter?
For Example:
I found a Trick to freeze water in about half a second, in this trick, When I open caps of a plastic bottle of cold water, cold Water freezes in a chain process, You can see the freezing process.
What is physics of The process of freezing water?
Yep, you're right, we can only talk about the phase of matter if we have a collection of molecules. It wouldn't make any sense to talk about a single molecule as being a solid, liquid, or gas because what matters is how the kinetic energy of the molecules (related to temperature) compares to the intermolecular bonding energy.
Solid: KE << BE
Liquid: KE < BE
Gas: KE >> BE
I think the context that this sentence appeared in adds further clarity, so I've included it below.
Here's the full paragraph along with Fig. 3:
The key distinction between the three classes of molecules is summarized in the bottom portion of Fig. 3. Small molecules may appear as solid, liquid, and gaseous phases without decomposition, while rigid macromolecules keep their bonding to nearest neighbors (their molecular integrity) only in the solid state. Due to internal rotation, flexible macromolecules can attain sufficient intramolecular disorder to melt (or dissolve) without breaking strong bonds. This property is at the root of many of the useful properties of polymers (plastic and rubber–elastic behavior in addition to high strength, light weight, and low melting temperatures). The three classes of molecules are thus very distinct in their phase behavior. No macromolecule can be evaporated thermally without decomposition. If one tries to place flexible macromolecules into the gas phase by evaporation of small solvent molecules from a dispersion of droplets of a solution with only one macromolecule per droplet, the macromolecules become microphase particles and collect at the bottom of the container [9].
What they were calling "sulphurous acid" back then is not what we would call an acid today. It was anhydrous sulphur dioxide which has a boiling point of $-10^\circ$C.
When liquid sulphur dioxide was poured into the red-hot vessel, due to the Leidenfrost effect, it would form itself up into globules and float on a layer of its own vapour. In this state the temperature of the globules would be just below that of its boiling of $-10^\circ$C as it evaporates away at a now greatly reduced rate. Pouring in a small amount of water, which freezes at $0^\circ$C, while the sulphur dioxide is in this state results in it freezing within a few seconds. Once all the sulphur dioxide has evaporated off, the ice will quickly melt again before being brought up to just below its boiling point of $100^\circ$C as it assumes its spheroidal form due to the Leidenfrost effect. If one is quick, before all the liquid sulphur dioxide has disappeared one can thrown out a small lump of ice from a red-hot crucible!
Update with a Reference
A source confirming the liquid sulphurous acid was indeed (anhydrous) sulphur dioxide can be found on page 645 of volume 3 of Lehrbuch der Physik by O. D. Chwolson, a copy of which can be found here. To quote, on the sixth and seventh lines down from the top of the page Chwolson writes (in German)
Boutigny brachte flüssige SO$_2$, welche bei $-10^\circ$C siedet, in einen glühenden Platintiegel, $\ldots$
which in English translation roughly reads
Boutigny brought liquid SO$_2$ [sulphur dioxde], which boils at $-10^\circ$C, into a glowing platinum crucible, $\ldots$
Best Answer
If you mean what takes place in each transformation between different states of matter then you must first understand the components of each state. A solid: •The particles cannot move, only vibrate • The bonds that hold particles close together will be very tight • The solid will not be able to be deformed due to the fact, that the particles cannot get any closer, and the object will denser than a gas or liquid. A liquid: • The particles can move past one another but are still held so that they have a fixed volume • The particles are held together by loose bonds and they can move. • The liquid can be moulded to a shape and be deformed, it is not as dense as a solid but denser than a gas. A gas: • The particles can go anywhere and are not held by any bonds and can take on any form. • They can be moulded into any shape. •The gas is not as dense as liquid or solid. Plasma: •The particles are separate and the nuclei are apart from the electrons (ionization). A picture is below of the states of matter:
There is a graph to show changing states of matter below:
The graphs shows that when there is a mixture of states of matter the particles cannot heat up anymore due to the fact, certain states of matter cannot be above or below certain temperatures.
When freezing water specifically, (at a particle level), the bonds strengthen and the particles become locked into place, this results in ice which is solid and cannot be deformed. At an atomic level though, water is different to all other liquids, as it expands. This happens when water particles join together they must have a certain formation. This is because water is made up of 2 positive particles and one negative. The positive must pair with a negative, resulting in a gap between particles, this is shown in the picture below:
Hope that helps.