Ch 10 PPt. 4

  1. Amorphous Solids
    • particles are randomly arranged and have no ordered long-range structure
    • Example: rubber
  2. Crystalline Solids
    • particles have an ordered arrangment extending over a long range
    • - ionic, molecular, covalent network, metallic
  3. Ionic Solids
    • particles are ions ordered in a regular three dimensional arrangement and held together by ionic bonds
    • Ex: NaCl
  4. Molecular Solids
    • particles are moelcuels held together by intermolecular forces
    • Ex: ice
  5. Covalent Network SOlids
    • particles are atoms linked together by covalent bonds into a giant 3D array
    • Ex: quartz
  6. Metallic Solids
    particles are metal atoms whose crystals have metallic properties such as electricalconductivity
  7. Interference
    occurs when two waves pass through the same region of space
  8. Constructive interference
    occurs if the waves are in-phase, producing a wave with icnresaed intensity
  9. Destructive Interference
    occurs if hte waves are out-of-phase, resulting in cancellation
  10. Diffraction
    occurs when electromagnetic radiation is scattered by an object containing regularly spaced lines (like diffraction grating) or points (like atoms in a crystal)
  11. Coordination number of:
    body centered cubic 
  12. Coordination number of: 
    simple cubic
  13. Coordination number of: 
    hexagonal and cubic closest-packing
  14. Which packing takes up the most space?
    hexagonal and cubic
  15. unit cell
    a small repeating unit that makes up a crystal
  16. ionic crystals characteristics
    • charged species
    • generally hard/ brittle nad high melting point
    • conduct ONLY as melt or in a solution
  17. Molecular Crystal characteristics
    • held together by intermolecular forces
    • soft and low melting point
    • nonconducting
  18. Covalent (NEtwork) Crystals
    • held together by covalent bonds
    • generally hard and high melting
    • nonconducting
  19. Allotropes
    • different structural forms of an element
    • Carbon: graphite, diamond, fullerence, nanotubes
  20. __ is a molecular solid whose molecules have hte shape of a soccer ball with twelve pentagonal and twenty hexagonal faces and each carbon aton in sp2 hybridized
  21. __ consist of sheets of graphite rolled into tubes of 2-30 nm diameter.
    carbon nanotubes
  22. Metallic Crystals: 
    • BCC, FCC, or Hex arrangement
    • Positive ions in a "sea" of electrons
    • Variable hardness and melting point
    • All conduct
  23. A __ is a graphical display of the temperatures and pressures at which two phases of a substance are in equilibrium.
    phase diagram
  24. Triple Point
    the only condition under which all three phases can be in equilbrium with one another
  25. Critical Temperature
    the temperature above which the gas phase cannot be made to liquefy at any pressure
  26. Critical Pressure
    the minimum pressure required to liquify a gas at its critical temp
  27. Supercritical Fluid
    a state of matter beyond the critical point that is neither liquid nor gas
Card Set
Ch 10 PPt. 4
Chapter Ten