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"best" lewis structure

Posted: Wed Oct 26, 2016 7:55 pm
by Salma Sudarmadji 2I
When drawing the "best" lewis structure, do the most electronegative atom always receive the charge in ionic bonds?

Thanks

Re: "best" lewis structure

Posted: Wed Oct 26, 2016 8:17 pm
by paulapedrani
The best Lewis structure is one where the FC is zero. Ideally, you want the FC to be between one and negative one. The overall charge is the same as each one's FC combined. So if it's CN-, you would want the addition of all the formal charges to be negative one

Re: "best" lewis structure

Posted: Fri Oct 28, 2016 2:04 am
by Brandon_Wu_2L
Additionally you would rather have the central atom have a FC of 0. If FC=0 cannot be achieved for all the atoms, it is better to put the negative FC on the most electronegative atom.

Re: "best" lewis structure

Posted: Fri Oct 28, 2016 2:27 pm
by Jasleen Kaur 1J
Yes. when forming the bonds you want to try and get the central atom with fc of 0.