Bonding and structure

• Ionic bonding is the electrostatic force of attraction between oppositely charged ions and its structure is an ionic lattice examples of this are sodium chloride and magnesium oxide
• Covalent bonding are shared pair of electrons and they can form two different structures simple molecular and macromolecluar
• Simple molecular: with intermolecular forces (van derby waals, permanent dipole, hydrogen bonds) between molecules.
• Examples of simple molecular are iodine, ice, carbon dioxide, water, methane
• Macromolecular are giant molecular structures for example diamond graphite silicon dioxide and silicon
• Metallic bonding is the electrostatic force of attraction between the positive metal ions and the delocalised electrons and they form a giant metallic lattice. Example are magnesium sodium and all metals
• Only use the words molecules and intermolecular forces when talking about simple molecular substances
• Boiling and melting points of ionic is high because of giant lattice of ions with strong electrostatic forces between oppositely charged ions
• Boiling and melting point of simple molecular is low because of weak intermolecular forces between molecules (specify type e.g van derby waals, hydrogen bonding)
• Boiling and melting points of macromecular is high because of many strong covalent bonds in macromolecular structure. Take a lot of energy to break the many strong bonds
• Boiling and melting points of metallic is high because of the strong electrostatic forces between positive ions and sea of delocalised electrons
• Ionic have generally good Solubility in water
• Simple molecular have generally poor Solubility in water
• Macromolecular and metallic are insoluble in water
• In an ionic lattice ions can't move meaning they have poor conductivity when solid
• In simple molecular have no ions to conduct and electrons are localised (fixed in place) they have poor conductivity when solid
• Macromolecular structures such as diamond and sand are poor conductors when solid because electrons can't move
• Macromolecular structures such as graphite are good conductors when solid because free delocalised electrons between layers
• Metallic have good conductivity when solid because delocalised electrons cab move through structures
• Ionic conductivity when molten is good because ions can move
• Simple molecular have poor conductivity when molten because they have no ions
• Macromolecular have poor conductivity when molten
• The general description of ionic is crystalline solids
• The general description of simple molecular are mostly gases and liquids
• The general description of macromolecular are solids
• The general description of metals are shiny, malleable as the positive ions in the lattice are all identical so the planes of ions can slide easily over one another, attractive forces in the lattice are the same whichever ions are adjacent