[Plumbum]

Hi everyone

I have difficulties with the binding energy and I hope that somebody can help me out! The task is to order these atoms by their binding energy ( from lowest zo highest)
The atoms are C, Si, Ge, Pb, Sn and I should explain why. So I ordered them this way : Pb,Sn,Ge,Si,C
due to electronegativitiy.

I'm really not sure , if its correct this way , please help me out.

thank u !

[rwiew]

Hey, it won't be the electronegativity that matters, at least not the only factor definitely. What do you know about binding in solids, band structures etc.?

[Plumbum]

I don't really know what you mean, sorry!
(I'm from Germany sorry )

I'm actually wondering how I can estimate which atom has the higher binding energy neither considering the MO nor the electronegativity..:/

[AdiDex]

If you are talking about binding energy of a whole atom....
Then you should not consider the binding energy of a electron (which depends upon electronegativity etc.)

ITS ALL about binding energy of a nuclei.. Since binding energy of a nuclei is millions-Billions times greater than binding energy of a electon (Also known as Ionization energy)...

For eg. For a Hydrogen atom binding energy of electron is just 13.6 eV whereas its binding energy of a nuclei is 28,300,000 eV...
So just forget about electronegativity...and please consider  Nuclear Force (Not Coulomb Force).

[Plumbum]

so how would you order these atoms  C, Si, Ge, Pb, Sn from lowest to highest...?

[AdiDex]

First tell me .
Of which isotopes are you talking about....
Its C12 or C14..?
If you talking about total binding energy then element having high mass will have higher binding energy...!!!!
And if you talking about binding energy per nucleon...then google binding energy curve you will get the answer....

[Plumbum]

well the task only said C so...

I ordered them this way:

Pb,Sn,Ge,Si,C

whereas C has the highest an Pb the lowest Bindingenergy..

[AdiDex]

I modified my reply...so please read it first

[AdiDex]

[AdiDex]

If you're talking about total binding energy ...
So i think the answer should be Pb , I , Sn , Ge , Si , C
And the C has least....and Pb has highest .
Since More Nucleons means More Nuclear Force .
So More Binding Energy..

But if the question is about binding energy per nucleon then answer will be different..

[Plumbum]

what would the answer be if the question was binding energy per nucleon ?

[AdiDex]

You can use this graph.

And here is your exact Answer....For Nuclear Binding Energy Per Nucleon

Ge-72 (8.73 MeV) ,
Sn-118 (8.51 MeV) ,
Si-28 (8.447 MeV) ,
I-127 (8.445 MeV ) ,
Pb-208 (7.86 MeV) ,
C-12 ( 7.686 MeV)

Note that there is tough competition between silicon and iodine ..(I checked only for One-one isotope of each element it may be possible  that another isotope of Iodine can have higher binding energy than Si )

By the way no one going to ask you this..

In general read this http://en.m.wikipedia.org/wiki/Nuclear_binding_energy#Nuclear_binding_energy_curve
 
I think it will help you.

[Plumbum]

thank u ! =) I appreciate your help