## Best way to start Lewis Structures

veneziaramirez 3I
Posts: 57
Joined: Fri Sep 29, 2017 7:07 am

### Best way to start Lewis Structures

What is the best way to start a Lewis structure? Draw all the electrons on each atom, then draw the bonds or draw the bonds then assign electrons?

manasa933
Posts: 72
Joined: Fri Sep 29, 2017 7:04 am

### Re: Best way to start Lewis Structures

I would say draw electrons and then bonds!

Jason Liu 1C
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Joined: Fri Sep 29, 2017 7:04 am

### Re: Best way to start Lewis Structures

I personally prefer drawing 1 bond between the central atom and each of the other atoms and then figuring out how many more bonds or lone pairs I need in order to have the right number of electrons

Karen Ung 2H
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### Re: Best way to start Lewis Structures

Normally, I'd draw the bonds to connect the atoms together first and then figure out how many electrons are left to distribute amongst the structure. It's helpful to know how the formal charge equation plays a role in each atom when assigning bonds. For example, oxygen has six valence electrons, so normally it'd like to have one double bond and two lone pairs.

Lourick Bustamante 1B
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Joined: Wed Nov 16, 2016 3:02 am

### Re: Best way to start Lewis Structures

I usually like to draw one bond between each of the atoms and then I assign the rest of the valence electrons!

Nathan Tu 2C
Posts: 46
Joined: Fri Sep 29, 2017 7:07 am

### Re: Best way to start Lewis Structures

After counting how many electrons I have, I always like to look at the name and try to base my model around that. For example, the only way you would arrive at the structure for CH^3SH and HOCO would be by looking at the name and basing your structure around that.

Jessica Benitez 1K
Posts: 50
Joined: Fri Sep 29, 2017 7:04 am

### Re: Best way to start Lewis Structures

I usually start by counting all the valence electrons and finding out the central atom, which is the one with the lowest ionization energy. I start with one bond between the central atom and remaining atoms and then fill in the remaining electrons keeping the formal charge as low as possible.

Sandhya Rajkumar 1C
Posts: 50
Joined: Fri Jun 23, 2017 11:40 am

### Re: Best way to start Lewis Structures

I first find out what the central atom is, and then I draw a single bond between the central atom and each of the other atoms. I then fill in all of the remaining electrons with either bonds or lone pairs and try to keep the formal charge as close to 0 as possible.

Peri Bingham 1G
Posts: 50
Joined: Fri Sep 29, 2017 7:03 am

### Re: Best way to start Lewis Structures

I do a guess and check method essentially. I draw the central atom and connect all the atoms to the central atom with a bond and then add electrons until all atoms have 8 electrons. Then I figure out the formal charge and move around atoms and bonds and keep checking the formal charge until I believe I have found the most stable configuration.

Morgan Baxter 1E
Posts: 50
Joined: Thu Jul 27, 2017 3:00 am

### Re: Best way to start Lewis Structures

First I count all of the valence electrons involved in the bonding. If you do not get this step right, your structure will be off. Then I figure out what is the central atom and place the other atoms around it. Then I put a single bond between each, because you know that there will at least be a single bond. Then I use common sense, guess and check, and formal charges in order to determine the correct lewis structure.

DAllaf
Posts: 20
Joined: Fri Sep 29, 2017 7:04 am

### Re: Best way to start Lewis Structures

In the first step it's essential to total up how many valence electrons you are working with, because without it you're answer will be off. Next, try looking at the name of the molecule and analyze the elements within it to figure out what the central atom will be. From there try piecing it together by starting off with single bonds, keeping in mind of radicals and also using the formal charge equation.

Hope this helps!

204917020
Posts: 31
Joined: Fri Apr 06, 2018 11:05 am

### Re: Best way to start Lewis Structures

First, find out how many total valence electrons youll need, find the central atom (the atom with the lowest ionization energy), then, fill out the atoms with lone pairs according to the octet rule. Count all the valence electrons, if there are too many, add double bonds as needed and remove the extra lone pairs.

Rummel Requerme 1E
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### Re: Best way to start Lewis Structures

Figure out how many valence electrons that the given elements have. The central atom is usually the one with the smallest ionization energy (know the periodic trend!) and then figure out how many electrons need to be shared to achieve an octet. Use double bonds, etc. accordingly to avoid having excess electrons (more or less than what you need!).