4 ms·

I thought "metal" exclusively referred to a metal element, but it seems the definition is broader than that: (http://en.wikipedia.org/wiki/Metal http://en.wiki

by 6ren 13y ago

I thought "metal" exclusively referred to a metal element, but it seems the definition is broader than that: (http://en.wikipedia.org/wiki/Metal http://en.wikipedia.org/wiki/Metal) Many elements and compounds that are not normally classified as metals become metallic under high pressures.

mikeash 13y ago
Don't forget the astronomers, for whom a metal is any element that isn't hydrogen or helium.
- scarmig 13y ago
  Add enough pressure and you can even get metallic hydrogen, which has been predicted to be a room temperature superconductor. Not that you'd want to be in any room with that kind of pressure (250k atm).
  - btilly 13y ago
    But if this is true and can be demonstrated, I guarantee that there are people who will want to try to commercialize it.
    - obviouslygreen 13y ago
      Perhaps I'm misreading your phrasing... but why wouldn't they?
      - btilly 13y ago
        It is hard to commercialize a substance that we are unable to create/maintain the conditions to use. But if someone can demonstrate how to make and hold solid hydrogen in a configuration where superconduction can be demonstrated at room temperature, then you've clearly gone several steps towards addressing feasibility, and you've demonstrated the existence of potential commercial opportunities.
tedsanders 13y ago
To most physicists, a metal is something that conducts electricity AND gets more conductive as it gets colder. The second condition is important to distinguish metals from insulators and semiconductors. (This is a good, but not perfect, definition.)
marcosdumay 13y ago
Metal is a substance where the electrons flow "freely" in a lower potential created by the nuclei. That's different from, for example covalent crystals, where electrons are "locked" into a region, and ionic composts, where electrions distribution is quite like the one on free atoms. Now, I put "free" and "locked" inside quotes because they are not completely so. There is a continuum, and no substance is at the extrema. Also, at astronomy "metal" has a completely different meaning.

by 6ren 13y ago

mikeash 13y ago

Don't forget the astronomers, for whom a metal is any element that isn't hydrogen or helium.

scarmig 13y ago
Add enough pressure and you can even get metallic hydrogen, which has been predicted to be a room temperature superconductor. Not that you'd want to be in any room with that kind of pressure (250k atm).
- btilly 13y ago
  But if this is true and can be demonstrated, I guarantee that there are people who will want to try to commercialize it.
  - obviouslygreen 13y ago
    Perhaps I'm misreading your phrasing... but why wouldn't they?
    - btilly 13y ago
      It is hard to commercialize a substance that we are unable to create/maintain the conditions to use. But if someone can demonstrate how to make and hold solid hydrogen in a configuration where superconduction can be demonstrated at room temperature, then you've clearly gone several steps towards addressing feasibility, and you've demonstrated the existence of potential commercial opportunities.

tedsanders 13y ago

To most physicists, a metal is something that conducts electricity AND gets more conductive as it gets colder. The second condition is important to distinguish metals from insulators and semiconductors. (This is a good, but not perfect, definition.)

marcosdumay 13y ago

Metal is a substance where the electrons flow "freely" in a lower potential created by the nuclei. That's different from, for example covalent crystals, where electrons are "locked" into a region, and ionic composts, where electrions distribution is quite like the one on free atoms. Now, I put "free" and "locked" inside quotes because they are not completely so. There is a continuum, and no substance is at the extrema. Also, at astronomy "metal" has a completely different meaning.