## Formal Charge

$FC=V-(L+\frac{S}{2})$

Posts: 72
Joined: Fri Sep 28, 2018 12:19 am

### Formal Charge

Can someone explain the other way to determine the formal charge? The formula used in class confuses me and I am aware there is another, clearer way!

ElliotPourdavoud 1A
Posts: 36
Joined: Fri Sep 28, 2018 12:16 am

### Re: Formal Charge

Another way is to count each electron that surrounds the atom in question and give it a value of 1 (ex. if an atom has 1 lone pair, you count both electrons as 1) then you count each bond as 1, (ex. if an atom has 2 bonds each bond is counted as 1) then you just add those values together and subtract from the valence electrons of the atom. Ex. If an atom has 6 valence electrons, and two lone pairs and two bonds, its formal charge is 0 because the 2 lone pairs = 4 and the two bonds = 2, 6-6= 0.

Grace Kim 1J
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Joined: Fri Sep 28, 2018 12:18 am
Been upvoted: 1 time

### Re: Formal Charge

Instead of using the formula, a shortcut in finding the formal charge is (number of valence electrons - number of the dots/number of lines).

Here is a good youtube video I found explaining how to use the shortcut method!
Hope this helps!

Millicent Navarro 1I
Posts: 61
Joined: Fri Sep 28, 2018 12:25 am

### Re: Formal Charge

Personally, the way I look at calculating the formal charge is through this equation:
Number of valence electrons - (Lone pairs + Bonds)

# of valence electrons: Given through the periodic table based on their period position (Ex: Carbon has 4 V.E. because it is located in Period 4.)
Lone pairs: The number of "dots" around an element
Bonds: The number of "lines" in between two elements

Anmol_cheema_2F
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

### Re: Formal Charge

Basically the formula can be see as FC= # of valence electrons-( # of dots + # of lines)
the # of dots are just the lone pairs and the # of lines is just the S/2 or number of bonds between atoms

yea-lyn pak_1G
Posts: 30
Joined: Fri Sep 28, 2018 12:18 am

### Re: Formal Charge

You can just count the number of dots (each electron in a lone pair) and the number of lines (the number of pairs of electrons). Then subtract the number you counted from the number of valence electrons the atom has.

Anand Narayan 1G
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Joined: Fri Sep 28, 2018 12:15 am

### Re: Formal Charge

The one I find the most helpful is # of valence electrons - (Lone electrons + Bonds)

Arlene Linares 3A
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Joined: Fri Sep 28, 2018 12:25 am

### Re: Formal Charge

Grace Kim 1E wrote:Instead of using the formula, a shortcut in finding the formal charge is (number of valence electrons - number of the dots/number of lines).

Here is a good youtube video I found explaining how to use the shortcut method!
Hope this helps!

Thank you for the video.

Jack Hewitt 2H
Posts: 67
Joined: Fri Sep 28, 2018 12:27 am

### Re: Formal Charge

Number of valence electrons - (number of lone electrons + number of lines drawn)