1. Draw the Lewis Structure
* Nitrogen is the central atom.
* Oxygen has 6 valence electrons each.
* The ion has a -1 charge.
The Lewis structure for nitrate has one double bond to oxygen and two single bonds to oxygen. Each single bonded oxygen has a lone pair of electrons.
2. Determine the Number of Valence Electrons
* Nitrogen (N) has 5 valence electrons.
* Oxygen (O) has 6 valence electrons, and there are 3 oxygens.
* The ion has an extra electron due to the -1 charge.
Total valence electrons: 5 + (6 * 3) + 1 = 24
3. Assign Electrons to the Atom
* Nitrogen: It has 4 electrons from the bonds (2 from the double bond and 1 from each single bond) and no lone pairs.
* Double Bonded Oxygen: It has 2 electrons from the double bond and 4 electrons from two lone pairs.
* Single Bonded Oxygen: It has 1 electron from the single bond and 6 electrons from three lone pairs.
4. Calculate the Formal Charge
* Formal Charge = (Valence Electrons) - (Non-bonding Electrons) - (1/2 Bonding Electrons)
* Nitrogen: 5 - 0 - (1/2 * 8) = +1
* Double Bonded Oxygen: 6 - 4 - (1/2 * 4) = 0
* Single Bonded Oxygen: 6 - 6 - (1/2 * 2) = -1
5. Distribute Formal Charges
To minimize the formal charge, the negative charge is distributed between the two single-bonded oxygens.
Therefore, the formal charge of nitrogen in the nitrate ion is +1.
