Ch.12 - Solids and Solid-State Materials
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- Diffraction of X rays with l = 131.5 pm occurred at an angle of 25.5 degrees by a crystal of aluminum. Assuming first-order diffraction, what is the interplanar spacing in aluminum? (LO 12.2) (a) 76.4 pm (b) 183.1 pm (c) 305.5 pm (d) 152.7 pm
Problem 2
- Niobium oxide crystallizes in the following cubic unit cell:
Problem 5
What is the formula of niobium oxide, and what is the oxidation state of niobium? (LO 12.5) (a) NbO, Nb = +2 (b) Nb2O, Nb = +2 (c) NbO2, Nb = +4 (d) Nb2O3, Nb = +3
- The following diagrams represent the electron population of the composite s–d band for three metals—Ag, Mo, and Y:
Problem 6
Which diagram corresponds to which metal? (LO 12.7) (a) Ag = 3, Mo = 1, Y = 2 (b) Ag = 2, Mo = 1, Y = 3 (c) Ag = 2, Mo = 3, Y = 1 (d) Ag = 1, Mo = 2, Y = 3
- Examine diagrams for the electron population of the composite s–d band for three metals in question 6. Which metal has the highest melting point? (LO 12.7) (a) Metal 1 (b) Metal 2 (c) Metal 3
Problem 7
- The following diagrams represent the electron population of molecular orbitals for different substances. What diagram corresponds to magnesium oxide, germanium, and tin? (LO 12.8)
Problem 8
(a) Diagram 1 = tin, diagram 2 = magnesium oxide, diagram 3 = germanium (b) Diagram 1 = germanium, diagram 2 = magnesium oxide, diagram 3 = tin (c) Diagram 1 = germanium, diagram 2 = tin, diagram 3 = magnesium oxide (d) Diagram 1 = magnesium oxide, diagram 2 = tin, diagram 3 = germanium
- The molecular orbital diagram of a doped semiconductor is shown below. If the semiconductor is silicon, does the diagram represent n-type or p-type doping and which of the following elements could be dopant? (LO 12.9)
Problem 9
(a) n-type, As (b) n-type, Ga (c) p-type, As (d) p-type, Ga
- If the band-gap energy of a gallium phosphide (GaP) semiconductor is 222 kJ/mol, calculate the wavelength of light emitted in a GaP light-emitting diode (LED). (LO 12.11) (a) 186 nm (b) 245 nm (c) 539 nm (d) 854 nm
Problem 11
- A superconductor is a material that loses all electrical resistance below a characteristic temperature called the superconducting transition temperature. Which graph represents the behavior of a superconductor? (LO 12.13) (a)
Problem 13
(b)
(c)
(d) Problem 18b
Identify each of the following kinds of packing: (b)
Problem 18d
Identify each of the following kinds of packing: (d)
- The following compound undergoes a phase transition from the solid to the smectic liquid crystal phase at 121 °C. Upon further heating, the compound undergoes another transition to liquid phase at 131 °C.
Problem 19
(b) Which image represents the arrangement of molecules at 135 °C?
- Titanium oxide crystallizes in the following cubic unit cell:
Problem 20
(b) What is the formula of titanium oxide?
Problem 22a
The following diagrams show the electron populations of the bands of MO energy levels for four different materials: (a) Classify each material as an insulator, a semiconductor, or a conducting metal.