Editing Isoelectronicity (section)

==Examples==
{{multiple image
|align = right
|total_width = 315
|image1 = L-serine-2D-skeletal.png
|caption1 = [[Serine]]
|image2 = L-cysteine-2D-skeletal.png
|caption2 = [[Cysteine]]
|image3 = L-selenocysteine-2D-skeletal.png
|caption3 = [[Selenocysteine]]
|footer = Three isoelectronic amino acids
}}
{{multiple image
|align = right
|image1 = Dimethyl ether Structural Formulae.svg
|width1 = 150
|caption1 = Dimethyl ether
|image2 = (E)-Azomethane.svg
|width2 = 150
|caption2 = Azomethane
|footer = Both molecules have the same electron configuration, but due to the double bond and extra atom in azomethane, they are not isoelectronic 
}}

The {{chem|N|link=nitrogen}} atom and the {{chem|O|+|link=oxygen}} ion are isoelectronic because each has five [[valence electron]]s, or more accurately an electronic configuration of [He] 2s<sup>2</sup> 2p<sup>3</sup>.

Similarly, the [[cation]]s {{chem|K|+|link=potassium}}, {{chem|Ca|2+|link=calcium}}, and {{chem|Sc|3+|link=scandium}} and the [[anion]]s {{chem|Cl|-|link=chloride}}, {{chem|S|2-|link=sulfide}}, and {{chem|P|3-|link=phosphide}} are all isoelectronic with the {{chem|Ar|link=argon}} atom. 

{{chem|CO}}, {{chem|CN|-|link=Cyanide}}, {{chem|N|2}}, and {{chem|NO|+}} are isoelectronic because each has two atoms triple bonded together, and due to the charge have analogous electronic configurations ({{chem|N|-}} is identical in electronic configuration to {{chem|O}} so {{chem|CO}} is identical electronically to {{chem|CN|-}}).

[[Molecular orbital diagram]]s best illustrate isoelectronicity in diatomic molecules, showing how [[atomic orbital]] mixing in isoelectronic species results in identical orbital combination, and thus also bonding.

More complex molecules can be polyatomic also. For example, the [[amino acid]]s [[serine]], [[cysteine]], and [[selenocysteine]] are all isoelectronic to each other. They differ by which specific [[chalcogen]] is present at one location in the side-chain.

{{chem|CH|3|COCH|3}} ([[acetone]]) and {{chem|CH|3|N|2|CH|3}} ([[azomethane]]) are not isoelectronic. They do have the same number of electrons but they do not have the same structure.