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Roy_06
Oct2-04, 11:28 PM
If you looked at a picture of where an electron would be likely to be found in a hydrogen atom, would the electron picture look the same regardless of temperature?

Edit: would the electron have a definite distance from the nucleus at 0 K and not just a likely place to be found?

Tide
Oct2-04, 11:36 PM
No, it would be temperature dependent. The atom will be in any of (a combination of) many possible excited states.

Roy_06
Oct3-04, 12:42 PM
Can you answer my question though about if the temperature was 0 K, would an electron would remain at a fixed distance from the nucleus?

geometer
Oct3-04, 12:45 PM
Can you answer my question though about if the temperature was 0 K, would an electron would remain at a fixed distance from the nucleus?

It would just have a likely place to be found. This is a basic principle of quantum mechanics that as far as I know is not temperature dependent.

mrjeffy321
Oct3-04, 01:55 PM
well at 0 K, idealy there wouldnt be any volume at all (since you can possibly take any more energy out of the atom and move the electon farther in) because with an ideal gas, at absolute zero, there is no volume, but then you cant do that, (with an atom) so there must be some minicuel distance between the nucleus and electon, but I dont know of a way to find it if there even is such a way.

Galileo
Oct3-04, 02:54 PM
A single hydrogen atom doesn't have a temperature, because temperature is only a useful quantity when dealing with a huge number of molecules/atoms.
If the hydrogen gas is very cold (around 0 K), then your hydrogen atom will likely be in the ground state (lowest energy). The probability distribution for the position of the electron will not be strongly centered about a fixed distance from the nucleus though.
If the gas is hot, then the atom will likely be in an excited state.

geometer
Oct3-04, 02:58 PM
The temperature of a substance is related to the motion of the atom as a whole, and does not effect the energy levels of the electrons in the substance. The electron energy levels in an atom have a lowest energy state, known as the ground state, and lowering the temperature would not lower the energy level associated with the ground state.

Roy_06
Oct3-04, 08:15 PM
Ok if a raindrop had greater temperature than another raindrop would the electrons of the first, on average, be farther from the nucleus than the electrons of the second?

Gonzolo
Oct3-04, 09:15 PM
Ok if a raindrop had greater temperature than another raindrop would the electrons of the first, on average, be farther from the nucleus than the electrons of the second?

It is quite general that an increase in temperature causes an increase in volume (metals, crystals, gases etc.). It is clear that the interatomic distances increase in these cases. For metals and crystals, it follows that electron distribution will be adjusted.

geometer
Oct3-04, 10:06 PM
It is quite general that an increase in temperature causes an increase in volume (metals, crystals, gases etc.). It is clear that the interatomic distances increase in these cases. For metals and crystals, it follows that electron distribution will be adjusted.

It causes and increase in volume because the distance between atoms gets larger. The electron locations around the atoms don't change.

Gonzolo
Oct3-04, 11:03 PM
The energy levels of a single Fe atom are not the same as as those of crystalline Fe. The energy levels of an atom depend on what potentials are nearby. If distances between atoms change, so will the local potential of an electron, thus so will its energy levels. Granted that it is not by much, and that it will mostly concern the outer electrons, less so the core electrons. For Fe, the outer electrons of a single atom become free in the crystalline case.

spacetime
Oct4-04, 01:58 AM
The functions of state like temperature, pressure and prperties like color, odour etc. are defined only for macrostates. You can't talk of the temperature of a hydrogen atom.

Temperature is a measure of macroscopic avg. of the K.E. of all such particles like molecules and atoms.

So, you can't change the temp. of a Hydrogen atom. Because it doesn't have any.


spacetime
www.geocities.com/physics_all/index.html

Chronos
Oct4-04, 02:27 AM
All atoms have a ground state energy [called ZPE]. That assures every atom has a thermal signature. Quantum theory forbids any atom from reaching a temperature of absolute zero