1. Start with the neutral atoms:
* Phosphorus (P): Has 15 protons and 15 electrons.
* Oxygen (O): Has 8 protons and 8 electrons.
2. Account for the number of each atom:
* Phosphorus: 1 atom x 15 electrons = 15 electrons
* Oxygen: 4 atoms x 8 electrons = 32 electrons
3. Add the extra electrons from the charge:
* The phosphate ion has a -3 charge, meaning it has gained 3 electrons.
4. Calculate the total:
* 15 electrons (Phosphorus) + 32 electrons (Oxygen) + 3 electrons (Charge) = 50 electrons
Therefore, a phosphate ion (PO₄³⁻) has 50 electrons.
