Structure and Properties of Ionic Bonding

Ionic Bonding 

• Ionic bonding is the strong electrostatic force of attraction between oppositely charged ions. 
• Metals lose e- (electrons) to form positive ions - cations 
• Non-metals gain e- to form negative ions - anions 
• e.g. Ionic bonding in sodium chloride.

Structure of Ionic Compounds

• Ionic compounds form a giant ionic lattice held together by many strong ionic bonds.

• Each Cl^- is surrounded by 6 Na⁺
• Each Na⁺ is surrounded by 6 Cl^-

• A similar structure is seen with MgO but this is stronger as the Mg²⁺ ion is bonded more strongly to O²⁺. 

Properties of Ionic Compounds

• High MP (melting point) & BP (boiling point) - there are many strong ionic bonds to break due to strong electrostatic attraction between oppositely charged ions.
• Crystalline - the ions are packed together regularly.
• Brittle - the arrangement of ions allows crystals to split easily.
• Soluble in water - Water is a polar molecule. These molecules are electrostatically attracted to the +ve (positively charged) and –ve (negatively charged) ions in the lattice, and pulls it apart.
• If the attractions between the water molecule are stronger than the attractions between the ionic lattice, it will dissolve.