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• Metallic bonding


  The type of bonding you get between metal atoms
• Metals bond to non-metals through ionic bonding
• Non-metals bond to other non-metals through covalent bonding
• Metallic bonding

  Metals bond to other metals
• Metallic bonding


  1. Atoms give up their outer shell electrons

  2. Electrons become delocalized

  3. Strong electrostatic attraction between positive ions and negative electrons

  4. Holds everything together in a regular structure
• Metallic bonding


  • Gives metals strength and high melting/boiling points
  • Metals are good conductors of electricity and heat
  • Metals are malleable
• Alloy


  Contains two or more different elements, either by mixing together two different metals or a metal and a non-metal
• Alloys


  • Combination of different sized atoms disrupts the metal's regular structure
  • Layers can no longer slide over one another
  • Alloy is much harder than pure metal
• Alloy


  • Steel (mostly iron, also contains 1-2% carbon, sometimes chromium, manganese or vanadium)
• Covalent bond


  Atoms form by sharing electrons
• Ionic bond


  Atoms form by transferring electrons from one to the other
• Atoms transfer electrons


  To get a full outer shell
• Atoms share electrons to get a full outer shell when they are both non-metals
• Dot and cross diagram


  Shows which electrons belong to each atom
• Displayed formula


  Writes chemical symbols and uses lines to show covalent bonds
• 3D model


  Shows the actual 3D arrangement of atoms
• Displayed formulas don't show 3D shape, 3D models do
• Ammonia (NH3)


  • 1 nitrogen atom
  • 3 hydrogen atoms
  • Nitrogen needs 3 extra electrons, hydrogens need 1 each
• Drawing covalent bonds in ammonia

  1. Draw atoms and outer shells

  2. Determine how atoms can share electrons to fill shells

  3. Draw dot and cross diagram

  4. Draw displayed formula
• Simple molecular substances


  Small molecules with strong covalent bonds between atoms, but weak intermolecular forces between molecules
• Polymers


  Long chains made of repeating monomer units
• Giant covalent structures


  Structures with billions/trillions of atoms joined by covalent bonds in a regular lattice, very strong
• Giant covalent structures


  • Silicon dioxide
  • Diamond
  • Graphite
• Ionic bonds


  Bonds formed between atoms with opposite charges due to electrostatic forces
• Ions


  Atoms that have lost or gained electrons, forming a positive or negative charge
• Formation of ions


  1. Atom loses electrons to become a positive ion

  2. Atom gains electrons to become a negative ion
• Chloride ion formation


  • Chlorine atom gains 1 electron to form Cl- ion
• Ionic compound


  Compound formed by the attraction between oppositely charged ions
• Dot and cross diagram


  Diagram showing the arrangement of electrons in an ionic compound, with one atom's electrons as dots and the other as crosses
• Drawing dot and cross diagram for MgCl2

  1. Draw magnesium with 2 outer electrons

  2. Draw 2 chlorines each with 7 outer electrons

  3. Magnesium transfers 1 electron to each chlorine

  4. Resulting in Mg2+ and 2 Cl- ions

  5. Arrange ions with Mg2+ in the middle and Cl- on either side