ZolarV Posted September 25, 2009 Posted September 25, 2009 i know this must be a dumb question, but can metal exist in the gas state? if not then what forces exist that restrict metals from being a gas, i would think it would be the electro-magnetic weak force or universal gravitation.
hermanntrude Posted September 25, 2009 Posted September 25, 2009 gases can certainly exist as gases. Google manganese dioxide thermite Merged post follows: Consecutive posts mergedalso don't fluorescent lights contain mercury? is that metallic mercury? not sure...
ZolarV Posted September 25, 2009 Author Posted September 25, 2009 No, i mean what about a metal as an element not a compound, because compounds can certianly achieve any state possible by just adding the right chemicals. like could there be an copper gas, and if so would it be able to pass electicity better due to its increased energy level, or would the space between atom negatively affect conductivity
Sisyphus Posted September 25, 2009 Posted September 25, 2009 (edited) Anything can be a gas. Get solid copper hot enough, and it will melt. Get it hotter still, and it will boil. What keeps it from happening at lower temperatures are the molecular bonds, specifically metallic bonding. As for electrical conductivity, metals generally lose a lot (about half) when they become liquids, and pretty much don't conduct at all as gases. As plasma, everything conducts electricity. Edited September 25, 2009 by Sisyphus
insane_alien Posted September 25, 2009 Posted September 25, 2009 copper gas wouldn't be a good conductor (although at temperatures where it is a gas it is likely to be ionized as well and plasmas are good conductors so maybe).
swansont Posted September 25, 2009 Posted September 25, 2009 Look at a phase diagram. Even when the bulk is in solid form, there will often be a vapor present, though at a small partial pressure. I rely on this to get vapor into the vacuum system in order to trap atoms. The vapor pressure of alkalis is going to be small — of order 10^-8 torr at room temperature, but there is definitely vapor present. Metals should be similar.
hermanntrude Posted September 26, 2009 Posted September 26, 2009 No, i mean what about a metal as an element not a compound, because compounds can certianly achieve any state possible by just adding the right chemicals. like could there be an copper gas, and if so would it be able to pass electicity better due to its increased energy level, or would the space between atom negatively affect conductivity both my examples were of metals as elements in the gas phase
swansont Posted September 26, 2009 Posted September 26, 2009 copper gas wouldn't be a good conductor (although at temperatures where it is a gas it is likely to be ionized as well and plasmas are good conductors so maybe). The reason being that metals are good conductors because of the band structure of the electron levels, and the presence of electrons in the conduction band. You lose this in a (non-plasma) gas
timo Posted September 26, 2009 Posted September 26, 2009 I'm wondering whether this [half-filled conduction bands or more generally mobile electrons] isn't what qualifies a substance as a metal - not the (mixture of) atoms contained. It would be my spontaneous understanding of the term (no need to tell me that Wikipedia has an article called "metal", btw). In that case the answer to the question is probably "no, metals cannot be gaseous".
UC Posted September 26, 2009 Posted September 26, 2009 gases can certainly exist as gases. Google manganese dioxide thermite Merged post follows: Consecutive posts mergedalso don't fluorescent lights contain mercury? is that metallic mercury? not sure... Mercury vapor. While it may not conduct any better than normal gas, once an arc is struck, the plasma is an excellent conductor. For a particularly awesome looking piece of equipment, google mercury arc rectifier. As for nomenclature, the gas may not participate in metallic bonding anymore, but it is still of a 0-valent metallic element.
hermanntrude Posted September 26, 2009 Posted September 26, 2009 Mercury vapor. While it may not conduct any better than normal gas, once an arc is struck, the plasma is an excellent conductor. For a particularly awesome looking piece of equipment, google mercury arc rectifier. As for nomenclature, the gas may not participate in metallic bonding anymore, but it is still of a 0-valent metallic element. I have one of those demo sets for showing atomic emission. One of the tubes contains mercury which you can see is liquid before you turn on the current but it vaporises when the current is on... I always assumed fluorescent lamps worked the same
Justonium Posted September 27, 2009 Posted September 27, 2009 Lol, I accidentally made some gaseous metal yesterday. Look at the thread 2 below yours, titled "What caused this explosion?" if you're curious.
John Cuthber Posted September 27, 2009 Posted September 27, 2009 Any metal at any temperature above absolute zero will have a vapour pressure. For some metals like mercury the vapour pressure is quite high and, at a few hundred degrees, mercuty boils. That doesn't address the question of whether or not the mercury vapour is a metal. Metals conduct electricity well, are shiny and so on. Mercury vapour doesn't and isn't. One of the defining properties of a gas is that the interactions between the atoms or molecules are small. One of the defining properties of a metal is that those interactions are large. No metal is a gas.
hermanntrude Posted September 28, 2009 Posted September 28, 2009 it all depends on how you define a metal. For most people a metal is simply any element to the left of the staircase line. Certainly the high attractions between the atoms and the lustrousness and greyish (or goldish) colour are all characteristics, but the definition is simply that it's to the left of that line.... of ourse the reason for that line lies in the fact that things to the right are electronegative and the things to left are electropositive, but that's a bit of a generalisation too...
John Cuthber Posted September 28, 2009 Posted September 28, 2009 I doubt that this statement is true, "For most people a metal is simply any element to the left of the staircase line." I think most people recognise metals as the shiny stuff. Agricola didn't have any difficulty writing de re metallica even though the periodic table had yet to be thought of. Only a chemist would characterise the metals by their position in the periodic table. If you are not sure about this check with an astrophysicist.
hermanntrude Posted September 28, 2009 Posted September 28, 2009 technically, hydrogen is a metal. An alkali metal. The whole thing is bit fuzzy, hey?
John Cuthber Posted September 29, 2009 Posted September 29, 2009 Quite a lot of elements- hydrogen is one example, are metals in one allotrope, but not in another. There is no definitive answer to the question "is tin a metal?" because you need to know which form it's in. I don't see why that's different from the idea that mercury (for example) may, or may not be a metal depending on what form it is in. It's a metal in the solid and liquid states- but not when it's a gas.
Mr Skeptic Posted October 7, 2009 Posted October 7, 2009 Regardless of whether the element is normally a metal, it will have no metallic bonding in the gas phase. A non-metallic metal if you will. On the other hand, things like hydrogen or oxygen that don't normally behave like a metal can be cooled/compressed enough, and then will be metallic.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now