central atom

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Lauren Bui 1E
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Joined: Sat Jul 20, 2019 12:15 am

central atom

Postby Lauren Bui 1E » Fri Nov 01, 2019 8:22 pm

When drawing a lewis structure, how do you determine which atom goes in the center?

Ryan Narisma 4G
Posts: 88
Joined: Fri Aug 30, 2019 12:18 am

Re: central atom

Postby Ryan Narisma 4G » Fri Nov 01, 2019 8:35 pm

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!

Cassidy Kohlenberger 3D
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Joined: Wed Sep 18, 2019 12:19 am

Re: central atom

Postby Cassidy Kohlenberger 3D » Fri Nov 01, 2019 8:48 pm

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.

Arianna Perea 3H
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Joined: Thu Jul 25, 2019 12:17 am

Re: central atom

Postby Arianna Perea 3H » Fri Nov 01, 2019 11:33 pm

why is the central atom the one with the least electronegativity?

HuyHa_2H
Posts: 85
Joined: Wed Sep 11, 2019 12:15 am

Re: central atom

Postby HuyHa_2H » Sat Nov 02, 2019 2:14 am

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.

Julieta Serobyan4D
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Joined: Wed Sep 11, 2019 12:17 am

Re: central atom

Postby Julieta Serobyan4D » Sat Nov 02, 2019 2:33 am

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

AniP_2D
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Joined: Sat Aug 17, 2019 12:17 am

Re: central atom

Postby AniP_2D » Sat Nov 02, 2019 10:11 am

The least electronegative atom is the central atom when drawing Lewis structures.

Joowon Seo 3A
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Re: central atom

Postby Joowon Seo 3A » Sat Nov 02, 2019 1:02 pm

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.

Abigail_Hagen2G
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Joined: Fri Aug 09, 2019 12:17 am

Re: central atom

Postby Abigail_Hagen2G » Sat Nov 02, 2019 1:51 pm

It's the least electronegative because it's the one that can form the most bonds

Emily_4B
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Joined: Wed Sep 18, 2019 12:21 am

Re: central atom

Postby Emily_4B » Sat Nov 02, 2019 2:44 pm

Would using the element with the lowest ionization energy be synonymous to the lowest electronegativity?

Michelle Xie 3A
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Re: central atom

Postby Michelle Xie 3A » Sat Nov 02, 2019 5:19 pm

Use the element with the lowest electronegativity.

Ashley Osorio
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Joined: Thu Jul 11, 2019 12:17 am

Re: central atom

Postby Ashley Osorio » Sun Nov 03, 2019 12:54 am

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.".

Kayla Maldonado 1A
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Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

Re: central atom

Postby Kayla Maldonado 1A » Sun Nov 03, 2019 1:28 am

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.

305376058
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Joined: Thu Jul 11, 2019 12:17 am

Re: central atom

Postby 305376058 » Sun Nov 03, 2019 10:59 pm

The atom in the center should be the one with the least electronegativity.

Venus_Hagan 2L
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Joined: Fri Aug 02, 2019 12:16 am

Re: central atom

Postby Venus_Hagan 2L » Sun Nov 03, 2019 11:04 pm

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.

Clarice Chui 2C
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Joined: Fri Aug 30, 2019 12:16 am

Re: central atom

Postby Clarice Chui 2C » Sun Nov 03, 2019 11:12 pm

Also, Hydrogen will never be the central atom just fyi!

jmtz1I
Posts: 30
Joined: Wed Sep 18, 2019 12:15 am

Re: central atom

Postby jmtz1I » Sun Nov 03, 2019 11:17 pm

The atom with the least electronegativity is the one that is the central atom.


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