Geology 401

Unit I. Atoms, Bonds, and Crystals

  1. The Electronic Structure of Atoms  (Faure, pp. 60-72)
    1. What makes one element chemically different from another?
    2. To what extent are electrons Òstuck withÓ a particular nucleus?
    3. To what extent are they able to hop from one nucleus to another?
    4. In general, how does the filling of orbitals dictate the electronic structure of atoms?
  2. Chemical Bonds, Ionic Radii
    1. When are electrons ÒstolenÓ and when are they ÒsharedÓ between adjacent nuclei?
    2. How do elements vary in their tendency toward ÒthieveryÓ or ÒdonationÓ according to the filling of electronic orbitals?
    3. How do bonds behave when they are ionic?  Covalent?
    4. What controls the bond distances for bonds between various elements?
    5. How do the so-called ionic radii vary with valence and atomic number?
    6. Which bonds exhibit some Òdirectional stiffnessÓ?
  3. Ions in water (Faure, 87-89)
    1. What is the electronic structure of the H2O molecule?
    2. How does this structure encourage dissolution of ionic substances?
    3. How do covalent, non-ionic substances behave in water?
    4. In general, how do cations interact with the water molecules surrounding them in solution?
    5. What determines the effective size of an ion in water?
  4. Ions in Crystals (Faure, 87-105)
    1. In general, how does a cation of a given size fit together with oxygen or other anions crowded around it in a crystal?
    2. What are the general rules for determining if an element can substitute for another element in a crystal?
    3. If a substituting ion has a different charge than the ion it replaces, how does the crystal maintain neutrality?
    4. How do we describe the partitioning of an element between a liquid and a crystal precipitated from that liquid?
    5. How can we use this partitioning to determine temperatures or mineral formation in some cases? 
  5. Ions in silicate liquids
    1. How are silicate liquids different from crystals?
  6. Spectroscopy: Photon-matter interactions
    1. What do we call photons that are emitted when electrons fill vacancies in the lower energy levels of atoms?
    2. Why do excited atoms emit radiation only at certain wavelengths and not at all wavelengths?
    3. In general, how do these wavelengths change as the number of protons in the nucleus changes?
    4. What sorts of energetic transitions are responsible for emission of photons of the following types:

                                                     i.     Visible light

                                                      ii.     Infrared light

                                                        iii.     Ultraviolet light

                                                       iv.     Very high energies- greater than x-rays

 

  1. The players on the field of geochemistry.
    1. What are the general characteristics the following elements:  H, He, Li, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Ti, Cr, Mn, Fe, Ge, As, Se, Br, Kr, Rb, Sr, Ag, Cs, Ba, Au, Hg, Pb, Lanthanides, Actinides.  For each, know:

                                                     i.     Rough abundance

                                                      ii.     Common valence(s) in nature

                                                        iii.     Size (qualitative) for each valence

                                                       iv.     Tendency to form ionic or covalent bonds

                                                      v.     Electronegativity (qualitative)

                                                       vi.     Similarities with other elements

                                                         vii.     Siderophile, Chalcophile, Lithophile, or Atmophile?

                                                          viii.     Coordination when surrounded by oxygens

                                                        ix.     Solubility in water

                                                      x.     Gaseous forms

                                                        xi.     Favorite crystals- high T and P

                                                         xii.     Favorite crystals- low P and T