Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: neilep on 02/03/2006 04:22:45
-
Water freezes at 0 degrees C (32 Degrees F) eh ?
Does it continue to drop in temperature with the environment ?
How cold can ice get ?..by the way, I mean just ice made from your regular tap or rain water...
Men are the same as women.... just inside out !!
-
We'll this is an educated guess, but I am pretty sure that the temperature would decrease with the surrounding air. If ice stayed the same temperature, it would melt with the slightest increase in temperature meaning we would be flooded now, due to global warming. However if the temperature of the surrounding environment is -32 and the ice is -32 then there would need to be a 32.1 increase in temperature to melt the ice. This to me seems more reasonable.
-
is there even a limit to it? I mean it would still be ice just colder i don't think it turns into anything else
- Big T
-
Well there are 13 different states of matter. e.g beyond Solid and Gas
But to be honest I don't know :(
-
0°K
-
Yeah there is no reason that ice can't just get colder and colder until you reach absolute zero. Below 150K ice will form a slightly different structure called ice XI which is similar to normal ice but is ferroelectric - kind of like ferromagnetic but with electric fields. But this is still a kind of ice so you could get it as cold as you can get the surroundings (>0K).
-
just a thought - you may be thinking of a mixture of ice and water which will stay at a very stable temperature, as any energy that would otherwise be used in heating it up or cooling it down is used melting or freezing ice.
-
Thank you Dave,
It's just that I am sure in my distant past I heard something along the lines that ice stayed within a certain boundary of a temperature range, despite how cold the external ambient temperature was,...perhaps as you say, it was akin to a ' slush puppy' that I heard that.
Men are the same as women.... just inside out !!
-
Without its clothes pretty dam could!!
-
quote:
Originally posted by Mystericon
Well there are 13 different states of matter. e.g beyond Solid and Gas
Thirteen? I can only think of six. What are the thirteen?
-
i've heard of Solids, liquids, gases, plasmas, Bose-Einstein whats left
Michael
-
I FOUND 25, ARE THESE ALL PROPER STATES OF MATTER [:)]
PHYSICAL STATES OF MATTER
Gas
A gas is a substance which takes the shape of its container and expands to completely fill it's container. There are several types of gases with slightly different behaviors. These are ideal gasses, real gasses, super critical fluids, plasmas and critical opalescent materials.
Ideal Gas
Ideal gasses (sometimes called perfect gases) refer to the behavior which gasses approach as the pressure nears zero. This behavior is described mathematically by the ideal gas law. Although no gas behaves exactly as an ideal gas, many substances come very close to ideal behavior at atmospheric pressure and most behave ideally at very low pressures.
Real Gas
Most molecules attract one another until they come very close together, when they become repulsive. This attraction is due to the electrostatic interactions between the two molecules. These interactions are often categorized into dispersion forces, van der Waals forces, hydrogen bonding and dipole-dipole interactions. The repulsion between molecules at very close distances is due to the repulsion between the nuclei of the two molecules. These forces give rise to relationships between the pressure, temperature, volume and quantity of a substance which do not exactly obey the ideal gas law. Gasses under physical conditions which give non-ideal behavior are called real gasses.
Supercritical Fluids
At a given temperature, a gas can be compressed until it starts to condense into a liquid displaying a clear boundary between the liquid at the bottom of the container and the gas. Above a certain temperature, called the critical temperature, a gas can be compressed without ever observing a clear liquid - gas boundary. Gasses in this state are called super-critical fluids.
Critical Opalescence
The critical point is the temperature and pressure where the boundary between liquids and gasses ceases to exist and the substance becomes a supercritical fluid. Under this one set of physical conditions, the substance is neither gas or liquid. The substance will have liquid like regions of every size from the size of the container down to single molecules. As such there are regions of the size of every wave length of visible light and all wave lengths of light are refracted. This results in a milky, silvery appearing state called critical opalescence.
Plasma
A plasma is a material which has been heated to a temperature where molecules are not stable. In a plasma state, a substance is a mixture of neutral molecules, ions, atoms, clusters of atoms and free electrons. A spark is an example of a plasma.
Liquid
A liquid is a substance which takes the shape of it's container and has a fixed volume at a given temperature and pressure. A superfluid is a special type of liquid. Suspensions, colloids, liquid crystals and visceoelastic materials have properties intermediate between those of a liquid and a solid.
Superfluid
At very low temperatures certain compounds such as 3He will show a superfluid state. In this state quantum mechanical effects will be visible on a macroscopic scale. For example, spinning a sample of superfluid will give two or four counter rotating vortices in order to conserve angular momentum in the fluid as a whole rather than just at the atomic level.
Suspension
A material in which small solid particles are mixed uniformly with a liquid. A suspension behaves as a liquid.
Colloid
A colloid is a material which appears to be liquid but actually is a suspension of particles too small to observe with a microscope but bigger than normal molecules.
Liquid Crystal
In crystals the atoms are arranged in an ordered repeating pattern. In liquids there is no ordered pattern. In liquid crystals there is order in one or two directions while there is no order in the other directions. This gives a number of unique properties such as optical properties which can be turned off and on to make liquid crystal displays for watches and computers. There will also be changes in the viscosity of a substance when it reaches a liquid crystal phase.
Visceoelastic
Some compounds such as natural rubber appear to be solid when they are stretched, bent or set on a table top. However, over a period of time these materials will slowly deform to take the shape of the container. Substances which act as solid on short time scales and act as liquids on long time scales are called visceoelastic materials.
Solid
Solid state materials are characterized by having a fixed volume and shape. Crystals, glasses and elastomers are all types of solids.
Crystal
Crystals are solid state materials in which the atoms are arranged in an ordered repeating pattern. Many molecules will form crystals in which the original molecules are still distinguishable only stacked neatly. Organic compounds often form these molecular crystals. In other crystals, such as metal alloys, there is a repeating pattern but no distinguishable molecular units.
Glass
Glasses are amorphous solids, meaning that the atoms are not arranged in any repeating pattern. When a liquid is cooled very slowly it tends to form a crystal, while cooling quickly usually results in amorphous phases. Glasses are distinguished from elastomers by being brittle.
Elastomer
An elastomer is an amorphous solid which can be deformed with out breaking. A rubber band is an elastomer.
Superplastic
Many metals and alloys can be stretched by about 100% before breaking. Some alloys can be stretched by a few thousand percent before breaking. This is referred to as superplasticity.
Bose-Einstein Condensate
Atoms which are bosons behave according to Bose-Einstein statistics. Unlike fermions, many bosons can occupy the same quantum state. A laser beam is a collection of photons, which are bosons, all in the same quantum state, thus giving perfectly coherent light. At very low temperatures, atoms can all occupy the ground state of the system thus giving a coherent matter analogous to the laser. This process is called Bose-Einstein condensation.
Refractory
Refractory materials viewed on an atomic scale will have small domains of various crystal, liquid and amorphous states. Although this may sound like a very unstable material, refractory materials can be very stable. Refractory bricks are used for lining high temperature blast furnaces. Very little is known about the atomic structure of refractories and why they are so stable.
MAGNETIC STATES OF MATTER
Diamagnetic
A diamagnetic compound has all of it's electron spins paired giving a net spin of zero. Diamagnetic compounds are weakly repelled by a magnet.
Paramagnet
A paramagnetic compound will have some electrons with unpaired spins. Paramagnetic compounds are weakly attracted by a magnet.
Ferromagnet
In a ferromagnetic substance there are unpaired electron spins, which are held in alignment by a process known as ferromagnetic coupling. Ferromagnetic compounds, such as iron, are strongly attracted to magnets.
Ferrimagnet
Ferrimagnetic compounds have unpaired electron spins, which are held in an pattern with some up and some down. This is known as ferrimagnetic coupling. In a ferrimagnetic compound, there are more spins held in one direction, so the compound is attracted to a magnet.
Antiferromagnetic
When unpaired electrons are held in an alignment with an equal number of spins in each direction, the substance is strongly repelled by a magnet. This is referred to as an antiferromagnet.
Superconductor
Materials which will be repelled by magnetic fields because the magnetic field is excluded from passing through them. This property of superconductors is used to test for the presence of a superconducting state.
Michael
-
quote:
Originally posted by ukmicky
i've heard of Solids, liquids, gases, plasmas, Bose-Einstein whats left
Michael
Fermionic condensates, discovered/created in 2003. http://jilawww.colorado.edu/~jin/papers/FermiCondensatePreprint.pdf
-
Wow...excellent States Of Matter Michael !!...oh yeah !!...a real life-and-soul-of-the-party thing !! [;)]
Actually, it's very interesting....I had no idea how many ' states' there could be .......thanks.
-
michael
when chris sees your post he will"cream in his jeans"(can i say that)
you mentioned 3 different sorts of gas,and we all know he just loves gas [}:)][B)]
its the drugs,y-know.
-
quote:
Originally posted by ukmicky
Ideal Gas
Ideal gasses (sometimes called perfect gases) refer to the behavior which gasses approach as the pressure nears zero. This behavior is described mathematically by the ideal gas law. Although no gas behaves exactly as an ideal gas, many substances come very close to ideal behavior at atmospheric pressure and most behave ideally at very low pressures.
Seems to me that the nature of an ideal anything is that it is more a fiction than a reality, and as it says, no gas behaves exactly as an ideal gas, but all gases behave to a greater of lesser extent like an ideal gas.
quote:
Liquid
A liquid is a substance which takes the shape of it's container and has a fixed volume at a given temperature and pressure. A superfluid is a special type of liquid. Suspensions, colloids, liquid crystals and visceoelastic materials have properties intermediate between those of a liquid and a solid.
Visceoelastic
Some compounds such as natural rubber appear to be solid when they are stretched, bent or set on a table top. However, over a period of time these materials will slowly deform to take the shape of the container. Substances which act as solid on short time scales and act as liquids on long time scales are called visceoelastic materials.
So, are these two really different?
quote:
Superfluid
At very low temperatures certain compounds such as 3He will show a superfluid state. In this state quantum mechanical effects will be visible on a macroscopic scale. For example, spinning a sample of superfluid will give two or four counter rotating vortices in order to conserve angular momentum in the fluid as a whole rather than just at the atomic level.
Bose-Einstein Condensate
Atoms which are bosons behave according to Bose-Einstein statistics. Unlike fermions, many bosons can occupy the same quantum state. A laser beam is a collection of photons, which are bosons, all in the same quantum state, thus giving perfectly coherent light. At very low temperatures, atoms can all occupy the ground state of the system thus giving a coherent matter analogous to the laser. This process is called Bose-Einstein condensation.
Is not Bose-Einstein Condensate a variant of super fluidity.
http://physicsweb.org/articles/world/13/11/3
quote:
The first liquid in which superfluidity was recognized was helium-4 back in 1938. It loses its viscosity below 2.12 K. At the time Fritz London suggested that the phenomenon was associated with Bose-Einstein condensation (BEC), which occurs when an assembly of bosons (particles with zero or integer "spin") is cooled below a critical temperature. In Bose-Einstein condensation a large fraction of all the particles in the assembly congregate in the zero-momentum ground state.
Superfluidity was later discovered in liquid helium-3, which has a critical temperature of 2.4 mK - about 1000 times smaller than the temperature at which helium-4 becomes a superfluid. Since helium-3 atoms have a half-integer value of spin (i.e. they are fermions), the mechanism behind superfluidity in this system is somewhat different. At the critical temperature, the helium-3 atoms can link up to form Cooper pairs. Because each pair is a boson, the system can then undergo Bose-Einstein condensation like its cousin, liquid helium-4.
Most of the other bits look like they might be states of matter, but clearly not mutually exclusive states of matter.
For instance:
quote:
Suspension
A material in which small solid particles are mixed uniformly with a liquid. A suspension behaves as a liquid.
Clearly, one cannot say that a suspension is composed of solid particles, and then claim it is any other state than solid. It is a solid that is made to behave on a macroscopic level like a liquid, but it is still in the solid state.
On the other hand, there are clearly states of matter you have not included in your list.
The gravitational collapse of atoms into neutrons that happens in a neutron star.
Whether one can say the singularity in a black hole is matter at all is an interesting question.
There are probably many other non-atomic states of matter that we have not even started including in the list, let alone anti-matter (can it be matter if it is anti-matter?).
George
-
You certainly have a lot of states here. However, most of these are not true "states" if we're talking about pure materials. As soon as you add a second (or more) component to a system, properties can change dramatically.
Gas
Ideal gases only are theoretical entities, but in any case are just examples of gases. Many gases have properties very similar to ideal gases, but ideal gases don't exist in reality.
"Real gas" refers to any gas that exists.
A "supercritical fluid" is a type of gas that exists above its critical temperature and critical pressure. As long as you are above the critical temperature of a gas, that gas can not be condensed into a liquid. Exact definitions vary a bit, but this is my favorite).
"Critical opalescence" is a _property_ of supercritical fluids very near the critical temperature and pressure. Many properties are very odd in this region.
Liquids
A superfluid is a liquid that has no viscosity, but still a liquid. Superfluids will actually flow uphill.
Mixtures
Colloids, suspensions, etc. are mixtures, so are not generally considered separate "states".
Solids
Viscoelastic materials are generally considered to be solid. Note that even normal metals can flow given the right stresses. Also, glass used to be considered viscoelastic and was thought to be a supercooled liquid. This is now known to be false.
Refractory, crystalline, glass, etc. are simply different types of solid, not true "states" in the chemical sense.
DrDick
-
I was calibrating 2 thermometers, I placed one in my freezer & placed the other(Identical) in a small glass of water in the freezer also. The one in open air went to -2F, the one in the water went to 32 F . If ice can get as cold as the ambient temp , why did this happen? I also reversed the thermometers and the results were the same?