C2

• Ions 


  Ions are charged particles that can be a single atom or a group of atoms
• What happens when metals form ions ?

  Metals lose electrons when they form ions to form positive ions
• What happens when a non-metal form ions?

  Non-metals gain electrons to form negative ions
• What is the structure of an ionic compound called?

  Giant ionic lattice
• How are ions arranged?

  Ions are arranged in a lattice repeating of units of positive and negative ions
• Properties of ionic substances

  Ionic substances have a high melting and boiling point due to strong electrostatic forces between them

  They can conduct electricity when molten as ions are free to move and carry charge
• Ionic bonding 


  When a metal bonds to a non-metal. Metal atoms donate electrons to form ions
• Covalent bonding


  Atoms share electrons to gain full outer shell electrons
• Metallic Bonding 


  They form a lattice of ions surrounded by a sea of delocalised electrons. The electrons are free to move
• Solids 


  Particles are in a regular arrangements and they can vibrate around in fixed positions . Solids can't be compressed
• Liquid 


  Liquid particles have no regular arrangements . They are able to move past eachother and also can't be compressed
• Gas

  Gas particles are far apart and move at random speeds at random directions and can be compressed
• Diamond

  Diamonds are a giant covalent lattice , they have 4 covalent bonds per carbon atom

  Diamond has a high boiling point due to its molecular structure

  It is a poor conductor of electricity and is hard due to its rigid structure
• Graphite 


  Graphite has 3 covalent bonds per carbon atom and has hexagonal layers

  It has a high melting point due to strong covalent bonds

  Graphite can conduct electricity as it has a delocalised electron that is free to move and carry charge
• Allotrope 


  An allotrope is a structure made out of the same element but arranged differently
• Alloy 


  An alloy is a mixture of metals and different sized atoms that disrupt the lattice so layers can't slide over each other easily
• What are fullerenes and nano-tubes used for ?

  Medical purposes and electronic composites
• Why are fullerenes useful?

  They are useful because of the high surface to volume ratio so fewer are needed for purpose . Double the length = half the ratio
• Size of nano-particles and coarse particles

  Nano-particles = 100-250nm

  Coarse particles = >2500nm