Material science homework

MENG 3319 Chapter 1 & 2
Homework 1

  1. Cite the difference between atomic mass and atomic weight.
  2. Cite two important quantum-mechanical concepts associated with the Bohr
    model of the atom.
  3. Cite two important additional refinements that resulted from the wavemechanical atomic model.
  4. The atomic radii of Li
  • and O2− ions are 0.068 and 0.140 nm, respectively.
    (a) Calculate the force of attraction between these two ions at their equilibrium
    interionic separation (i.e., when the ions just touch one another).
    (b) What is the force of repulsion at this same separation distance?
  1. Briefly cite the main differences among ionic, covalent, and metallic bonding.
  2. Make a plot of bonding energy versus melting temperature for the metals listed in
    Table 2.3. Using this plot, approximate the bonding energy for copper, which has
    a melting temperature of 1085°C.
  3. Explain why hydrogen fluoride (HF) has a higher boiling temperature than
    hydrogen chloride (HCl) (19.4°C vs. −85°C), even though HF has a lower
    molecular weight.
  4. Calculate the %IC of the interatomic bond for the intermetallic compound TiAl3.
    On the basis of this result, what type of interatomic bonding would you expect to
    be found in TiAl3?
  5. Compute the %IC of the interatomic bond for each of the following
    compounds: TiO2, ZnTe, CsCl.
  6. What type(s) of bonding would be expected for each of the following materials:
    brass (a copper-zinc alloy), epoxy, barium sulfide (BaS), solid xenon, bronze,
    nylon, and aluminum phosphide (AlP)?
  7. What type(s) of bonding would be expected for steel (an alloy composed of iron
    with a very small amount of carbon)?
    (A) Ionic bonding
    (B) Metallic bonding
    (C) Covalent bonding with some van der Waals bonding
    (D) van der Waals bonding
  8. What type(s) of bonding would be expected for rubber?
    (A) Ionic bonding
    (B) Metallic bonding
    (C) Covalent bonding with some van der Waals bonding
    (D) van der Waals bonding
    MENG 3319 Chapter 1 & 2
  9. Classify each of the following materials as to whether it is a metal, ceramic, or
    polymer. Justify each choice: (a) brass; (b) magnesium oxide (MgO); (c)
    Plexiglas®; (d) polychloroprene; (e) boron carbide (B4C); and (f) cast iron.