Central Atom

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Michael Du 1E
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Joined: Sun Sep 22, 2019 12:16 am

Central Atom

Postby Michael Du 1E » Tue Nov 05, 2019 12:56 pm

Why is it that in some problems or molecules, the central atom doesn't follow the lower ionization rule? Say for example, CH3Br, I would assume Br would be the central atom since Br has a lower ionization energy as it has a larger radius. However, C would be the central atom rather than Br. thank you.

Rida Ismail 2E
Posts: 139
Joined: Sat Sep 07, 2019 12:16 am

Re: Central Atom

Postby Rida Ismail 2E » Tue Nov 05, 2019 1:32 pm

I just checked this and C does have the lowest IE.
Ionization energies:
C: 1086.5 KJ/mol
H:1312 KJ/mol
Br:1139.9 KJ/mol

Looking at this the IE of carbon is the lowest out of all of the atoms, therefore it goes in the center.

Avnita C_4B
Posts: 50
Joined: Sat Sep 14, 2019 12:17 am

Re: Central Atom

Postby Avnita C_4B » Tue Nov 05, 2019 2:33 pm

most of the times, the central atom is always the one with the lowest ionization energy. In this case, even though Br sounds like a perfect match, if you look up the ionization energy of the elements, carbon is slightly lower than bromine.

Posts: 61
Joined: Sat Sep 28, 2019 12:16 am

Re: Central Atom

Postby MMckinney_4H » Tue Nov 05, 2019 2:48 pm

Given that we can't look up stuff during the midterm, what would be the best way of figuring out which one goes in the middle for this situation?

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