1) Sodim will form cation Na⁺.
Electron configuration of sodium atom: ₁₁Na 1s² 2s² 2p⁶ 3s¹.
Sodium lost one valence electron to form cation with stable electron configuration as noble gas neon (atomic number 10).
2) Oxygen will form anion O²⁻.
Electron configuration of oxygen atom: ₈O 1s² 2s² 2p⁴.
Oxygen gain two valence electron to form anion with stable electron configuration as noble gas neon (atomic number 10).
3) Phosphorus will form cations P³⁺ and P⁵⁺, anion P³⁻.
Electron configuration for phosphorus: ₁₅ 1s² 2s² 2p⁶ 3s² 3p³.
Phosphorus lost five valence electron to form cation with stable electron configuration as noble gas neon (atomic number 10).
4) Ionic comounds: Na₂O (sodium oxide), Na₃P (sodium phosphide), Na₃PO₃ (sodium phosphite), Na₃PO₄ (sodium phosphate).
