Magnara - 24-9-2003 at 16:34
Why do some elements become diatomics and others don't?
chemoleo - 24-9-2003 at 17:43
do u actually expect an answer?
it's like asking why do things fall to the ground....
anyway, there are bimolecular elements as it's due to their electron configuration, i.e. O2 is O=O, indicating a double bond and indicating that
there are two electrons missing to fill up the orbital. For N2, it's the same story again, it forms via a triple bond and happens so due to
three electrons missing to fill the orbital.
If anyone thinks this is a high school explanation, sure, yes, it is, I can give u a proper one....but dont flame me for giving a cheap explanation!
jsut trying to be helpful t those needy souls out there.
End of message.
Blind Angel - 24-9-2003 at 18:04
I always wondered if metal become diatomic too, i was always told that only gases where. Li<sub>2</sub> or Li<sup>+</sup> ?
Mumbles - 24-9-2003 at 19:13
http://dl.clackamas.cc.or.us/ch104-08/elements.htm
That website could help to explain it a bit more. It goes into why metals don't form diatomic atoms. I think that its possible for metals to
form diatomic molecules, they'd just have a thermal stability of 0 K. So they can't exist anyway.
The way I remember what forms diatomic (or polyatomic ie Sulfur and Phosphorus) is it's its all non metals except Carbon. I guess the Nobel
gases are an exception too, but to me they're in their own group. There was also something about Genine(Jeanine) or something like that. It had
to do with the endings. ie hydro<u>gen</u>, Oxy<u>gen</u>, Chlor<u>ine</u>. I don't believe this includes
Astatine though. That probably why I don't remember it. You could always go with memorization.
Blind Angel - 25-9-2003 at 05:25
i think that to be diatomic it must be a gas at normal tempoerature but not a noble one, so all gases inm the Periodic table are diatomic exepted for
the last column
DDTea - 25-9-2003 at 10:43
It's really quite simple. Atoms are not happy unless they have enough valence electrons (that is, atoms in the outermost ring of the electron
cloud- usually 8).
Now, look at Oxygen, Nitrogen, and Chlorine. In all of these, they are very close to having a full outer ring of electrons- they require 2, 3, and 1
electrons, respectively. So, it would be a lot easier for them to form covalent bonds in order to gain electrons (actually in covalent bonding,
electrons are shared- but you understand what I mean). Also, since they require so few electrons to fill their outer shell, they are very
reactive...as such, they will bond with whatever is nearby.
So, Cl forms a single-bond with a second Cl atom, since each only need one atom to fill their electron shells (hence the sharing). O forms a double
bond with another O, and N forms a triple bond with another N (this triple bond is very strong and is why Nitrogen is so unreactive).
In the case of the Alkali metals, it wouldn't makes sense for them to form diatomic compounds. In their outer shell, they only have 1 electron.
As such, it is a lot easier for them to get rid of that electron, thus going down to a lower electron ring which is full, than it is for it to gain 7
more electrons. These, too, are very reactive elements for this reason.
And, carrying this logic further, that is why Alkalis bond so nicely with Halogens! Since Alkalis want to get rid of their 1 electron, and Halogens
want 1 more electron....they are friends!
Blind Angel - 25-9-2003 at 11:40
yeah but pure metal Lithium is what Li or Li<sup>-</sup> (sorry i just saw my error on the other post)
I think that Philou told me that they formed Li<sub>2</sub> which mystified me
[Edited on 25-9-2003 by Blind Angel]
kingspaz - 25-9-2003 at 14:09
its just Li.
simple as that. metals bond because their outer electrons aren't very strongly held. the outer electrons in a piece of metal are free to move
through the whole metal so in effect bond to every nucleus which they are near too. this is qhy metals are often strong. its also why they conduct.
the outer electrons are free to move from atom to atom. you need to do some reading to find out the basic principle sof bonding before we can help
with your question really.
Darkfire - 29-9-2003 at 16:51
Na2, Li2 both exist and O2 isnt really a double bond, and not really a single...
chemoleo - 29-9-2003 at 19:33
yes, the (non)existence of alkali diatomic compounds have been discussed before. see
http://www.sciencemadness.org/talk/viewthread.php?tid=329
Although it's not entirely conclusive, its of some use. have fun 
Blind Angel - 30-9-2003 at 07:16
That was exactly the topic I was looking for, thx chemoleo
Boandlkramer - 30-9-2003 at 08:05
I don't kow about the other stuff, but what i can tell is that H2 can be compressed and cooled (~10K) to form a kind of metal which is, by the
way superconducting.
maybe if you vaporised Li or so in a low pressure or vacuum environment...
But whats the use of all that anyway?