Electronegativity of Atoms: What are Determining Factors

Chemistry, Physics
[caption id="attachment_24637" align="alignright" width="480"] 5d molecular orbital - Image Dhatfield[/caption] When two different types of atom are bonded together, they do not share their bond electrons equally. This is because each type of atom possesses its own charge environment, which results in an atom’s electronegativity. Electronegativity is the measure of an atom’s ability to attract additional electron density to itself. For example, Sodium seeks to give an electron to become a positive ion, Na+. It has a very low electronegativity. Iodine wants to gain an electron to become a negative ion, I-. It has a relatively high electronegativity. Charge Environment Atoms vary in electronegativity, and bonds vary according to constituent atom electronegativities. The electronegativity of an atom depends upon its charge environment. That environment depends primarily on three things... Distance…
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Do Double Bonds Flip? Does Electron Density Move?

[caption id="attachment_7788" align="alignright" width="440"] 1,3,5 Hexatriene - NIST Image[/caption] How do double bonds flip, and what is the significance? The shorthand drawing of a double bond looks like an equal sign between two atoms. The double bond between the two carbon atoms of ethene gas, H₂C=CH₂, well illustrates this. Some organic compounds possess conjugated (alternating) double bonds. A simple example of this is 1,3,5-hexatriene. [caption id="attachment_7785" align="alignright" width="340"] Fig. 1. 1,3,5 Cyclohexatriene.[/caption] What If? But what if the ends of that 1,3,5 hexatriene are joined, with the loss of two hydrogen atoms, to make a ring one might be tempted to call 1,3,5-cyclohexatriene? In fact, such a molecule, if flipped left-to-right, is seen to be identical with 2,4,6-cyclohexatriene! The numbers can be dropped and the molecule can simply be named…
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