# The Naked Scientists Forum

### Author Topic: Does matter have the same volume at zero Kelvin and room temperature?  (Read 4082 times)

#### jccc

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##### Does matter have the same volume at zero Kelvin and room temperature?
« on: 17/04/2015 09:12:25 »
if electrons are circling around nucleus, they shall fall into lowest orbital at 0 K, therefore atom radius should become smaller, thus matter volume should become smaller?

why is water even has bigger volume when it iced?

« Last Edit: 17/04/2015 09:48:15 by chris »

#### alancalverd

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #1 on: 17/04/2015 12:49:12 »
1. No. Your atomic model is about 100 years out of date.

2. The free hydrogen bond angle dominates the structure of liquid water above 4 deg C. Below that temperature the material tends towards a lower energy state of regular tetrahedra packed in hexagonal symmetry (ice I) . Modifying the bond angle increases the effective packing radius of the molecule and hence reduces the density of bulk water as it freezes.

#### jccc

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #2 on: 17/04/2015 13:01:27 »
1. No. Your atomic model is about 100 years out of date.

2. The free hydrogen bond angle dominates the structure of liquid water above 4 deg C. Below that temperature the material tends towards a lower energy state of regular tetrahedra packed in hexagonal symmetry (ice I) . Modifying the bond angle increases the effective packing radius of the molecule and hence reduces the density of bulk water as it freezes.

thank you Alan.

1. my model is electron stable at atom radius, between electron and nucleus is negative charged fluid. what's your/new model, does electron moving or stable? what's the mechanism of orbital? how electron waves around the nucleus?

2. anything other than water increases volume when cooling down?

#### chiralSPO

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #3 on: 17/04/2015 14:34:22 »
1. No. Your atomic model is about 100 years out of date.

2. The free hydrogen bond angle dominates the structure of liquid water above 4 deg C. Below that temperature the material tends towards a lower energy state of regular tetrahedra packed in hexagonal symmetry (ice I) . Modifying the bond angle increases the effective packing radius of the molecule and hence reduces the density of bulk water as it freezes.

thank you Alan.

1. my model is electron stable at atom radius, between electron and nucleus is negative charged fluid. what's your/new model, does electron moving or stable? what's the mechanism of orbital? how electron waves around the nucleus?

2. anything other than water increases volume when cooling down?

1. Your fluid model is nonsensical and does nothing to address the questions you have about our models.

2. Bismuth also expands as it freezes. Probably some others, but can't think of them at the moment.

#### alancalverd

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #4 on: 17/04/2015 15:20:07 »
1. Read any modern (post-1940) textbook on chemistry

2. Printers' "hot metal" expands on cooling (not sure if it's used anymore!)

Remember the object of physics is to describe what happens, not to complain about it not fitting your preconceptions. In Eddington's words "the student of physics must become accustomed to having his common sense violated seven times before breakfast".

#### PmbPhy

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #5 on: 17/04/2015 17:33:28 »
Quote from: jccc
1. my model is electron stable at atom radius, ......

Quote from: jccc
...between electron and nucleus is negative charged fluid.
In real atoms there is no such thing as a "negative charged fluid" between electrons and the nucleus. There is only the electron surrounding the nucleus. That electron can be, and often is, described as an electron cloud. Read and learn:
http://en.wikipedia.org/wiki/Atomic_orbital

Quote from: jccc
...does electron moving or stable? what's the mechanism of orbital? how electron waves around the nucleus?
Electrons in atoms and molecules have very stable quantum states. The electron's wave function for the first few states of the hydrogen atom is described in the above link.

Quote from: jccc
2. anything other than water increases volume when cooling down?
Who knows. There are thousands if not millions of different kinds of liquids. Nobody knows offhand which ones behave in this manner. Whether it happens or not depends on the geometry. And water does decrease in volume with a decrease in temperature down to a certain temperature when the volume starts to increase again. I.e. during cooling water becomes more dense until reaching 3.98 °C. Read and learn:
http://en.wikipedia.org/wiki/Water
Quote
The maximum density of water occurs at 3.98 °C (39.16 °F). Most known pure substances become more dense as they cool, however water has the anomalous property of becoming less dense when it is cooled to its solid form, ice. During cooling water becomes more dense until reaching 3.98 °C. Below this temperature, the open structure of ice is gradually formed in the low temperature water; the random orientations of the water molecules in the liquid are maintained by the thermal motion, and below 3.98 °C there is not enough thermal energy to maintain this randomness. As water is cooled there are two competing effects: 1) decreasing volume, and 2) increase overall volume of the liquid as the molecules begin to orient into the organized structure of ice. Between 3.98 °C and 0 °C, the second effect will cancel the first effect so the net effect is an increase of volume with decreasing temperature. Water expands to occupy a 9% greater volume as ice, which accounts for the fact that ice floats on liquid water, as in icebergs.

#### chiralSPO

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #6 on: 17/04/2015 17:52:37 »
A quick point regarding the question itself: it is impossible (as far as we know) for matter to achieve zero Kelvin. We can use cryogens (like liquid helium) to get temperatures less than 5 K, and other techniques (like dopplar cooling http://en.wikipedia.org/wiki/Doppler_cooling or Raman cooling http://en.wikipedia.org/wiki/Raman_cooling; see also http://en.wikipedia.org/wiki/Ultracold_atom) to cool small quantities of matter down to within a few millionths or hundreds of billionths of a degree above absolute zero (down to about 10–7)

By the way: the fact that we can use light in these ways to cool down atoms is further evidence that our quantum mechanical models are correct.

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##### Re: Does matter have the same volume at zero Kelvin and room temperature?
« Reply #6 on: 17/04/2015 17:52:37 »