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central atom

Posted: Fri Nov 01, 2019 8:22 pm
by Lauren Bui 1E
When drawing a lewis structure, how do you determine which atom goes in the center?

Re: central atom

Posted: Fri Nov 01, 2019 8:35 pm
by Ryan Narisma 4G
Hi Lauren Bui 1E! To answer your question, to decide which element is the central atom, check which element has the least electronegativity (electron pulling power). I hope this helps!

Re: central atom

Posted: Fri Nov 01, 2019 8:48 pm
by Cassidy Kohlenberger 3D
In addition to referring to the electronegativity, I would look at the compound to see which atom is more likely to form bonds. For example, carbon forms four, nitrogen three, oxygen two, etc.

Re: central atom

Posted: Fri Nov 01, 2019 11:33 pm
by Arianna Perea 3H
why is the central atom the one with the least electronegativity?

Re: central atom

Posted: Sat Nov 02, 2019 2:14 am
by HuyHa_2H
The electron with the least electronegativity is the one that is the central atom but pretty much most of the time it's the element with the least amount of atoms in the molecule.

Re: central atom

Posted: Sat Nov 02, 2019 2:33 am
by Julieta Serobyan4D
Lauren Bui 1E wrote:When drawing a lewis structure, how do you determine which atom goes in the center?

If you do not know the electronegativity, you can basically count how many bonds each atom can form and then decide. For example, H in CH4 can form 1 bond, so it's logical to put C in the center

Re: central atom

Posted: Sat Nov 02, 2019 10:11 am
by AniP_2D
The least electronegative atom is the central atom when drawing Lewis structures.

Re: central atom

Posted: Sat Nov 02, 2019 1:02 pm
by Joowon Seo 3A
Usually if its the only atom: e.g. CH4, then C, the unique atom, would go into the center. But in general, it is the one with the least electronegativity.

Re: central atom

Posted: Sat Nov 02, 2019 1:51 pm
by Abigail_Hagen2G
It's the least electronegative because it's the one that can form the most bonds

Re: central atom

Posted: Sat Nov 02, 2019 2:44 pm
by Emily_4B
Would using the element with the lowest ionization energy be synonymous to the lowest electronegativity?

Re: central atom

Posted: Sat Nov 02, 2019 5:19 pm
by Michelle Xie 2B
Use the element with the lowest electronegativity.

Re: central atom

Posted: Sun Nov 03, 2019 12:54 am
by Ashley Osorio
This excerpt from the book helped me a bit figuring this out. "If there is doubt, a good rule of thumb for molecules other than compounds of hydrogen is to choose as the central atom the element with the lowest ionization energy. This arrangement often results in the lowest energy because an atom in the central posi- tion shares more of its electrons than does a terminal atom. Atoms with higher ionization energies are more reluctant to share and are more likely to hold on to their electrons as lone pairs.".

Re: central atom

Posted: Sun Nov 03, 2019 1:28 am
by Kayla Maldonado 1C
Arianna Perea 3H wrote:why is the central atom the one with the least electronegativity?

The least electronegative elements are in the center of lewis structures because an atom in the central position shares more of its electrons than does an atom on the sides of the central atom or the terminal position.

Re: central atom

Posted: Sun Nov 03, 2019 10:59 pm
by 305376058
The atom in the center should be the one with the least electronegativity.

Re: central atom

Posted: Sun Nov 03, 2019 11:04 pm
by Venus_Hagan 2L
The central atoms should be the least electronegative atom. My TA also mentioned that if you have a molecule and its like one of an element and 4 of another then the central atom will probably be the element that only has one.

Re: central atom

Posted: Sun Nov 03, 2019 11:12 pm
by Clarice Chui 2C
Also, Hydrogen will never be the central atom just fyi!

Re: central atom

Posted: Sun Nov 03, 2019 11:17 pm
by jmtz1I
The atom with the least electronegativity is the one that is the central atom.