Identify the correct formula for the compound formed between Mg²⁺ and PO₄^3- ions.

The correct answer is Mg₃(PO₄)₂.

Key Points

• The compound Mg₃(PO₄)₂ is formed due to the combination of magnesium ions (Mg²⁺) and phosphate ions (PO₄^3-) in a ratio of 3:2 to maintain charge balance.
• Magnesium has a charge of +2, while phosphate has a charge of -3. To neutralize the charges, three magnesium ions combine with two phosphate ions.
• The formula Mg₃(PO₄)₂ represents magnesium phosphate, a common ionic compound.
• Ionic compounds are formed by the electrostatic attraction between positively charged cations and negatively charged anions.
• This compound is often used in fertilizers and various industrial applications due to its phosphate content.

Additional Information

• Magnesium (Mg):
  • Magnesium is an alkaline earth metal with an atomic number of 12.
  • It commonly forms divalent cations (Mg²⁺) in chemical reactions.
  • It is essential for biological processes like enzyme activation and photosynthesis.
• Phosphate (PO₄^3-):
  • Phosphate is a polyatomic ion consisting of one phosphorus atom bonded to four oxygen atoms.
  • It carries a -3 charge and is widely found in biological systems and minerals.
  • Phosphates are critical for energy storage and transfer in cells (e.g., ATP).
• Ionic Compounds:
  • Ionic compounds are formed by the transfer of electrons, leading to cations and anions.
  • They exhibit high melting and boiling points due to strong ionic bonds.
  • Most ionic compounds dissolve in water, producing electrolyte solutions.
• Charge Balance in Ionic Compounds:
  • The ratio of ions in an ionic compound is determined by their charges to ensure overall neutrality.
  • For Mg₃(PO₄)₂, three Mg²⁺ ions neutralize the charge of two PO₄^3- ions.
  • This balance is a fundamental principle in chemical formula writing.