Bonding, structure and properties of matter

• What are giant covalent substances?

  They are solids with atoms covalently bonded together in a giant lattice.

  They have high melting and boiling points due to strong covalent bonds

  They mostly don't conduct electricity due to no delocalised electrons.

  Diamond, graphite and silicon dioxide
• Metallic bonding+ properties

  Forces of attraction between delocalised electrons and metal cations

  • High melting and boiling points due to strong electrostatic forces
  • Good conductors of heat and electricity because of delocalised electrons
  • Malleable because layers can slide over eachother
• What is ionic bonding?


  The electrostatic attraction between positive and negative ions
• What is a covalent bond?


  A shared pair of electrons between non-metals
• Properties of ionic substances

  • High melting and boiling points due to strong bonds
  • do not conduct electricity when solid due to ions being in fixed positions
  • conduct when molten or dissolved in water due to ions being free to move
• Structure and properties of simple molecular substances

  • Do not conduct electricity due to having no ions
  • they have weak intermolecular forces therefore have low melting and boiling points
  • most are gases and liquids at room temperature
• How are ionic compounds held together?

  • They are held in a giant ionic lattice with a regular structure
  • They have strong electrostatic forces of attraction between positive and negative ions which holds the structure together
• Describe and explain the properties of diamond

  • They have four covalent bonds for each carbon atom
  • Very hard due to strong bonds
  • very high melting points due to strong bonds
  • does not conduct electricty due to no delocalised electrons
• Describe and explain the properties of graphite

  • There are three covalent bonds for each carbon atom
  • They have layers of hexagonal rings
  • high melting points due to strong covalent bonds
  • layers are free to slide over eachother due to weal intermolecular forces
  • soft
  • can conduct electricity due to delocalised electrons between layers
• What are polymers?+ properties

  They are very large molecules with atoms linked together by covalent bonds

  They have high melting and boiling points due to many chemical bonds

  They can't conduct electricity
• What are alloys? why are they harder than pure metal?

  Alloys are a mixture of different metals

  They are harder because the different sizes of atoms distort the layers so they can't slide over eachother
• Describe and explain the properties of fullerene

  • They are a hollow shaped molecule
  • They are based on hexagonal rings but may ahve 5/7 carbon rings
  • they can be used to cage other molecules
  • huge surface area
• Describe and explain the properties of nanotubes

  • cylindrical fullerene with high length to diameter ratio
  • they have high tensile strength due to strong bonds
  • they are also conductive due to delocalised electrons
• State the uses of nanoparticles

  • medicine- drug delivery systems
  • electronics- conductive
  • cosmetics
  • wound dressings, deodrants- antibacterial properties
  • sun creams- better skin coverage and more effective protection