Terms in this set (24)

  • Ion
    Charged particle formed when atoms lose or gain electrons in order to produce a full outer shell.
  • Positive ion
    Formed when metal atoms lose electrons from their outer shell.
  • Negative ion
    Formed when non-metal atoms gain electrons to their outer shell.
  • Ionic bond
    Electrostatic attraction between ions of opposite charge.
  • Ionic compound
    Compound made up of positive and negative ions, key example: sodium chloride.
  • Covalent bond
    Shared pair of electrons found between non-metal atoms.
  • Simple molecule
    Molecule made up of a small number of atoms held by covalent bonds. Examples include water and ammonia. These are gasses and liquids because they are small molecules with only weak interactions between them.
  • Intermolecular forces (a.k.a. interactions)
    Weak force found between molecules, causes them to have a low m.m. and b.p.
  • Lattice
    Regular arrangement of particles.
  • Macromolecule
    Giant covalent structure made up of a large number of atoms.
  • Diamond
    Each carbon forms 4 covalent bonds to other carbon atoms resulting in a very hard substance.
  • Graphite
    Each carbon bonds to three others in a layered structure. Layers only have weak interactions between them making the material soft and slippery. Conducts electricity because of spare electron being delocalized.
  • Metal
    Giant structure of positive ions surrounded by a 'sea of electrons'.
  • Delocalised electrons
    Electrons that are free to move. Found in graphite and metals and cause them to conduct electricity.
  • Nanoscience
    Based on particles a billionth of a meter in size.
  • Polymer
    Long chain molecule made from many small molecules (monomers) joined together.
  • Thermosoftening polymers
    Can be melted and reshaped as have only weak interactions between chains.
  • Thermosetting polymers
    Cannot be remolded as have strong cross links between chains.
  • Alloy
    Mixture of metals which is harder that a pure metal because the different sizes of atoms. These disrupt the layers in the structure making it harder for them to slide past each other.
  • Shape Memory Alloy
    Return to original shape when deformed.
  • Buckminster Fullerine
    A football shaped cage of carbons which is used to deliver drugs through membranes into cells.
  • Electron configuration
    Illustrates the arrangement of electrons in their various shells. For example a Florine atom has a configuration [2,7] whereas a Florine ion has the configuration [2,8]⁻¹
  • Electron shell
    Shows how electrons are arranged around the nucleus. The first electron shell contains a maximum of 2 electrons. 2nd=8, 3rd=8, 4th=18
  • Electrical conductivity
    When a substance allows an electrical current to pass through it. This means that charges must be able to move and occurs in metals, graphite and molten ionic compounds.