Simple Molecular Covalent Structure Bonding Melting/ Boiling Points Reason Conductivity Solubility Giant Ionic Eg. NaCl Ionic bonds throughout lattice High Strong electrostatic attraction between oppositely charged ions Poor when solid ; good when molten or in aqueous solution Ions in fixed lattice when solid; lattice breaks down and ions become mobile. Good in polar solvents Attraction between ions in lattice and polar solvent Giant Metallic Eg. Mg Metallic bonds between positive ions and delocalised electrons Strong electrostatic attraction between ions and delocalised electrons Good Mobile electrons can move to carry charge Poor Forces within the molecule are too strong to be broken by solvents Giant Covalent Eg. Diamond Covalent bonds between atoms Strong covalent bonds between atoms No mobile electrons or ions Forces within lattice too strong to be broken by solvents Simple Molecular Covalent Eg. Cl2 Intramolecular covalent bonds; van der Waals’ forces between molecules Low Weak van der Waals’ between molecules – little energy required No mobile ions or electrons Good in non-polar solvents Van der Waals’ forces can form between the structure and the non polar solvent.