Diatomic Elements

[BPinthemorning]

Is there a reason that diatomic elements are diatomic? This is one of my extra credit questions, and I can use any resorces I can find, and APC is my first choice! Any help is apreciated.

[Mumbles]

It's a stability thing, along with positioning. Technically speaking, no element exists in a truely monatomic state***. Metals exist in a crystaline or otherwise lattice like form, which has a sea of electrons floating about. The metaloids, have a somewhat similar, but generally more arranged structure, something like graphite. While it may appear they are lone atoms, they are arranged in a way that stabilizes them. Every diatomic molecule is near the row of nobel gases. Like all other atoms, it wants to achieve nobel gas configuration. Alone, the monatomic species are quite reactive, as is the case with many seemingly monatomic species near the nobel gas configurations(alkali and alkaline earth metals. Even with a diatomic structure, the halides are still fairly reactive due to their single bond that is subject to various polarity shifts. While the alkali and alkaline earth metals are also near the nobel gases, they are stabilized by their metal structure, and due to the extra electrons, are unable to form bonds to achieve that structure. Bonding only serves to increase the number of electrons around the atoms, not decrease.

 

Other atoms below the diatomic ones in the same groups, you would expect to also exhibit diatomic binding. However they don't. The larger size, and ability to use the empty D electron levels allow for more complex structures. Phosphorus for instance exists in a tetrahedral shape, or a chain of tetrahedrons. Sulfur exists in a ring type shape. It also exists in a diatomic form as well, but it's not the natural form, so it doesn't count. The halides are diatomic for a different reason than N, and O are. The halides can only form one single bond, allowing for only a diatomic molecule. With N and O, they are gases. This largely prohibits the formation of larger more complex molecules(though ozone and something like pentazine do exist). They therefore bind together with each other. Due to the higher bond orders they must produce, they are much more stable, and thus less likely to be broken down.

 

 

 

*** I'm not sure where amorphous carbon comes in

 

 

 

 

That is probably much more than your teacher wants. Something like "They form diatomic molecules in order to gain an octet or nobel gas configuration, and be stable in the environment" will likely suffice.

[aquaman]

"Diatomic molecules are molecules made only of two atoms, of either the same or different chemical elements." -Wikipedia

 

So basically O2, H2, or any other element that is combined to itself.

 

(Di)- two (atomic)- atom (Molecule)- well.... molecule

 

So why diatomic molecules are diatomic? I don't know, may be they just feel better together?

 

Edit: never mind Mumbles pretty much sumed it up.

[hst45]

Is there a reason that diatomic elements are diatomic?

This almost sounds like a trick question. It could mean that:

 

A ) your teacher is really smart, or

 

B ) your teacher is dumber than a ham sandwich.

 

If A ), See Mumbles answer above

 

If B ), It's because "di" means two, and "atomic" means atoms.

 

O.K., I'm kidding, but maybe your teacher is a public school alumnus .

[aquaman]

I think there should be a Chemistry homework section just so we don't get a hundred "help me please" and clutter up the chemistry section. Don't get me wrong BPinthemorning it's just there doesn't need to be a new topic for every chem. question. Maybe rename this topic to like Chemistry Help and use it like the random thread but for chemistry questions... Just an idea

[Mumbles]

I did make one slight mistake. The nobel gases themselves can exist as truely monatomic atoms to my knowledge.

[BPinthemorning]

Dang, Mumbles!!! You go this stuff down! Thanks a ton! Next time I have a question, I will start a chemestry help thread.

[asilentbob]

With hydrogen for instance each monotomic H has 1 lone electron... so they both share them with each other so it like both "sorta" have a full orbital and hence stability... to get H2...

H-H

*Recall that - means 2 electrons...

*= means 2 bonds with 2 electrons... so 4 e-

 

With chlorine gas for instance each Cl has 7 electrons in its outer orbital... so it shares that last one with another Cl so that each "sorta" have 8 some of the time... ish... and hence stability... to get Cl2...

QuasiLewis dot diagram would be like:

:::Cl-Cl:::

 

O2... IIRC is different in that it has a double bond between...

QuasiLewis dot diagram would be like:

:=O::

 

N2... 5 e- in outer shell to give:

::N-N:: IIRC.

 

O3... 6 e- in outer shell to give:

:=O=O:: or the one with a 3x bond... hmm

Can't remember..

 

etc. Its all about electrons and outer orbitals getting filled for stability... just like with salts, etc... except its sharing instead of completely losing electrons...

[Mumbles]

Nitrogen has a triple bond.

 

Ozone is one single bond, and one double bond. In reality, it is more of a ring type thing, where the side oxygens can still share electrons, as the molecule isn't planar.