States of matter

• Solids


  Particles are lightly packed, vibrating about in a fixed position. Solids have a definite shape and a definite volume.
• Liquids


  Particles are highly packed, but are far enough apart to slide over one another. Liquids have an indefinite shape and a definite volume. Particles have more kinetic energy than solids, they can overcome some of the molecular forces.
• Gases

  Particles are very far apart and move freely. Gases have an indefinite shape and an indefinite volume.
• Solid


  • Liquid
  • Gas
• Diamond

  • Each carbon atom forms four covalent bonds with other carbon atoms in a giant covalent structure, so diamond is very hard, has a very high melting point and does not conduct electricity.
• Graphite

  • Each carbon atom forms three covalent bonds with three other carbon atoms, forming layers of hexagonal rings which have no covalent bonds between the layers. In graphite, one electron from each carbon atom is delocalized.
• Diamond and graphite


  • Also giant covalent structures, made of carbon
  • Diamond is the hardest natural substance
  • Graphite has layers which slide over each other, making it soft
  • Graphite conducts electricity but other covalent structures do not
• Nanoscience


  The science of very small particles. A nanometer is one millionth of a millimetre.
• Nanoscience


  • They can produce new useful properties in materials
  • They have a much bigger surface area to volume ratio than larger particles. This is very useful for substances such as catalysts.
• Carbon nanotubes

  • Made of carbon and only a few nanometers across
  • Bonding of carbon atoms are very strong
  • They are thin and long and conduct heat and electricity well.