13 Dec 2016 Is ethylene isoelectronic to dioxygen? Submitted by Chip Nataro, Lafayette College Yes 17% (1 vote) No 0% (0 votes) Well... 83% (5 votes) Total votes: 6 Log in or register to post comments Comments Depends on your definition of Robert Q. Topper, Cooper Union - December 13, 2016 - 2:16pm https://en.wikipedia.org/wiki/Isoelectronicity Using a similar internet Chip Nataro, Lafayette College - December 28, 2016 - 4:19pm Using a similar internet source, just typing isoelectronic into google, gives you the following definition: "having the same numbers of electrons or the same electronic structure". By the same number of electrons, the comparison of O2 and C2H4 fit this definition. However, in no way are they close in electronic structure, in which case they do not fit this definition.In fact, the wikipedia definition sited above defines isoelectronicity as "…the phenomenon of two or more chemical species (atoms, molecules, radicals, ions, etc.) differing in the atoms that comprise them but having the same number of valence electrons and the same structure (that is, the same number of atoms with the same connectivity)". Again, the same number of valence electrons is fine for the comparison of O2 and C2H4. However, they do not have the same structure or connectivity.I have a feeling that different people define this term in different ways. This is far from the only term for which that happens. Hopefully the poll got you to think about it a little bit.