5
$\begingroup$

I was reading on Wikipedia about how Pauling electronegativities are determined through

$$ \vert \chi_\ce{A} - \chi_\ce{B} \vert = \sqrt{E_\mathrm{d}(\ce{AB}) - \frac{E_\mathrm{d}(\ce{AA}) + E_\mathrm{d}(\ce{BB})}{2}}$$

At first, I thought I understood this since for an element like hydrogen the meaning of $E_\mathrm{d}(\ce{HH})$ is clear and easy enough to measure experimentally.

But I don't see how I would do the measurement in general. Do I have to make (unstable) diatoms and then try to measure the dissociation energy very quickly? Even the electronegativity for atoms with $Z > 100$ are known which baffles me. How do they measure these dissociation energies?

Improve this question
$\endgroup$
1
  • 1
    $\begingroup$ Off the top of my head, I believe the answer is that the element simply needs to bond covalently or metallically with itself when it is in its standard state. Its standard state doesn't need to be a diatomic. The metals form metallic bonds. The metalloids and non-metals (except the noble gases) form covalent bonds. For instance, carbon's standard state is graphite. The BDE for the C-C bond would then be the average energy it takes to break apart the C-C bonds in graphite. Other than the noble gases, I don't know of any elements that don't chemically bond with themselves. $\endgroup$
    – theorist
    Dec 1, 2021 at 5:35

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.