- Structure Overview
- PO3- contains one phosphorus atom and three oxygen atoms
- Phosphorus forms one double bond and two single bonds
- Oxygen atoms have negative (-1) charges and phosphorus (+1) charge
- Drawing Process
- Determine total valence electrons (24) by adding atomic numbers
- Place least electronegative atom (phosphorus) at center
- Mark lone pairs starting from outside atoms
- Calculate formal charges using formula: valence - nonbonding - ½ bonding
- Structure Optimization
- Convert lone pairs to bonds to minimize formal charges
- Final structure satisfies octet rule for all atoms
- Negative charge on most electronegative atom is best
- Draw brackets to indicate negative charge