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### Best way to start Lewis Structures

Posted: Sun Nov 19, 2017 11:46 am
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?

### Re: Best way to start Lewis Structures

Posted: Sun Nov 19, 2017 11:54 am
I would say draw electrons and then bonds!

### Re: Best way to start Lewis Structures

Posted: Sun Nov 19, 2017 2:55 pm
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

### Re: Best way to start Lewis Structures

Posted: Sun Nov 19, 2017 10:09 pm
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.

### Re: Best way to start Lewis Structures

Posted: Sun Nov 19, 2017 10:38 pm
I usually like to draw one bond between each of the atoms and then I assign the rest of the valence electrons!

### Re: Best way to start Lewis Structures

Posted: Sun Nov 19, 2017 10:42 pm
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.

### Re: Best way to start Lewis Structures

Posted: Mon Nov 20, 2017 12:34 am
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.

### Re: Best way to start Lewis Structures

Posted: Mon Nov 20, 2017 3:48 pm
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.

### Re: Best way to start Lewis Structures

Posted: Tue Nov 21, 2017 6:36 pm
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.

### Re: Best way to start Lewis Structures

Posted: Tue Nov 21, 2017 7:19 pm
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.

### Re: Best way to start Lewis Structures

Posted: Tue Nov 28, 2017 10:43 pm
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!

### Re: Best way to start Lewis Structures

Posted: Tue May 08, 2018 1:06 am
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.

### Re: Best way to start Lewis Structures

Posted: Sun May 13, 2018 8:29 pm
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!).