Structures (1.3)

• What is a metallic bond?

  Electrostatic attraction between ions and electrons
• What does bonding refer to?

  How atoms and ions are held together
• What does structure refer to?

  How atoms and ions are arranged in space
• What type of elements are involved in ionic bonding?

  Metal and non-metal
• What is the nature of the forces in ionic bonding?

  Electrostatic forces between oppositely charged ions
• What is covalent bonding?

  Shared pair of electrons between atoms
• What types of structures are associated with metallic bonding?

  Giant metallic lattice
• What is a giant ionic lattice?

  3D structure of oppositely charged ions
• What are the properties of a giant ionic lattice?

  • High melting and boiling points
  • Soluble in water
  • Conducts electricity when molten or in solution
• Why do giant ionic lattices have high melting and boiling points?

  Strong ionic bonds require much energy to break
• When do ionic compounds conduct electricity?

  When ions are free to move
• What is a simple molecular substance?

  Molecule with small numbers of atoms
• What are the properties of simple covalent molecules?

  • Low melting and boiling points
  • Do not conduct electricity
  • Insoluble in water
• Why do simple covalent molecules have low melting points?

  Weak van der Waals forces require little energy
• What is a giant covalent structure?

  3D structure of atoms joined by covalent bonds
• What are allotropes?

  Different forms of the same element
• What is the structure of diamond?

  3D tetrahedral structure with 4 bonds
• What is the structure of graphite?

  Hexagonal arrangement with 3 bonds
• How are the layers in graphite held together?

  By van der Waals forces between layers
• What is graphene?

  Single layer of graphite, one atom thick
• What are the properties of diamond?

  • High melting and boiling points
  • Very hard and strong
  • Insoluble in water
• What are the properties of graphite?

  • High melting and boiling points
  • Conducts electricity
  • Soft and slippery
• What are the properties of graphene?

  • High melting and boiling points
  • Excellent electrical conductor
  • Very strong and lightweight
• What is a metallic lattice?

  3D structure of positive ions and delocalized electrons
• What are the properties of metals?

  • Malleable and ductile
  • Good conductors of electricity
  • High melting and boiling points
• Why are metals malleable?

  Layers of ions can slide over each other
• Why are metals ductile?

  Can be drawn into wires without breaking
• Why do Group I metals have lower melting points than transition metals?

  Group I has 1 delocalized electron
• What is an alloy?

  A mixture of two or more elements, at least one metal
• What are the properties of alloys?

  • Distorted layers make them harder
  • Different sizes of atoms/ions
  • Retain metallic properties
• How is the percentage of gold in an alloy calculated?

  Carats × 100 / 24