## charge by square bracket

asalest 2K
Posts: 52
Joined: Wed Sep 30, 2020 9:39 pm

### charge by square bracket

HI,
What are the charges outside of the square brackets that the lewis structure is in? For example, Dr, Lavelle, put a - outside of the lewis structure for NO3 in his lecture today (11/02).

Chloe Little 3K
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### Re: charge by square bracket

It's just the charge of the molecule. So when writing the Lewis structure for the molecule NO3-, you would put brackets around the structure and a minus in the top right corner. It just depends on the charge of the molecule. For example, if the molecule's charge was +1, you'd put a + in the corner outside of the brackets.

Aayushi Jani 3A
Posts: 104
Joined: Wed Sep 30, 2020 9:51 pm

### Re: charge by square bracket

Yes, the charge represents the charge of the polyatomic ion/molecule. NO3 has a -1 charge, hence the -1 sign at the top right. This is because the Lewis structure drawing itself cannot showcase the specific charge of the molecule, so it is shown in this way.

Sami Siddiqui 1J
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### Re: charge by square bracket

The number on the top right corner of the brackets is used to denote the charge of the entire polyatomic species you're focusing on. If you were to calculate the formal charge of each of the atoms in the Lewis structure, you'll notice that the net formal charges will be equal to the charge of the entire molecule/formula unit as a whole. It's a pretty neat concept.

Funmi Baruwa
Posts: 108
Joined: Wed Sep 30, 2020 9:50 pm

### Re: charge by square bracket

the sign corresponds to the sign (charge of the molecule)! if the molecule is positively charged you would put a "+" if it is negatively charged you put a "-"

Hope this helps :)

Sejal Parsi 3K
Posts: 76
Joined: Wed Sep 30, 2020 10:03 pm

### Re: charge by square bracket

Hi! The sign corresponds to the charge of the molecule since the structure itself may not show it. If the ion is positive, there will be a positive sign outside the bracket; if the ion is negative, there will be a negative sign outside the bracket.

Anya Holbrook 1E
Posts: 91
Joined: Wed Sep 30, 2020 9:38 pm

### Re: charge by square bracket

Charges on the outside of a lewis structure depict the ionic charge of the molecule. For example, if the molecule is an anion, there would be a negative charge outside the brackets, with the coefficient depending on the molecule, and the same for cations as a positive charge.

Malakai Espinosa 3E
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### Re: charge by square bracket

The charge outside of the square bracket demonstrates the charge of the entire molecule. Because many of the structures we model are ions, they must have a charge. Using the sign outside the bracket is how we show that charge.

aashmi_agrawal_3d
Posts: 105
Joined: Wed Sep 30, 2020 9:39 pm

### Re: charge by square bracket

The charge represents the charge of the entire molecule. Since the charge of the molecule was -1, he put a minus. This allows for one to understand the number of electrons being represented in the lewis structure.