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Problem 27
An X-ray beam with λ = 154 pm incident on the surface of a crystal produced a maximum reflection at an angle of θ = 28.3°. Assuming n = 1, calculate the separation between layers of atoms in the crystal.
- An X-ray beam of unknown wavelength is diffracted from a NaCl surface. If the interplanar distance in the crystal is 286 pm, and the angle of maximum reflection is found to be 7.23°, what is the wavelength of the X-ray beam? (Assume n = 1.)
Problem 28
Problem 29a
Determine the number of atoms per unit cell for each metal.
(a) Polonium
Problem 29b
Determine the number of atoms per unit cell for each metal.
(b) Tungsten
- What is the packing efficiency of a body-centered cubic unit cell?
Problem 31
- What is the packing efficiency of a face-centered cubic unit cell? Please show your work.
Problem 32
Problem 33
Platinum crystallizes with the face-centered cubic unit cell. The radius of a platinum atom is 139 pm. Calculate the edge length of the unit cell and the density of platinum in g/cm3.
Problem 34
Molybdenum crystallizes with the body-centered unit cell. The radius of a molybdenum atom is 136 pm. Calculate the edge length of the unit cell and the density of molybdenum
Problem 35
Rhodium has a density of 12.41 g/cm3 and crystallizes with the face-centered cubic unit cell. Calculate the radius of a rhodium atom.
Problem 37
Plonium crystallizes with a simple cubic structure. It has a density of 9.3 g/cm3, a radius of 167 pm, and a molar mass of 209 g/mol. Use these data to calculate Avogadro's number (the number of atoms in one mole).
- Palladium crystallizes with a face-centered cubic structure. It has a density of 12.0 g/cm³, a radius of 138 pm, and a molar mass of 106.42 g/mol. Use these data to calculate Avogadro's number.
Problem 38
Problem 40b
Identify each solid as molecular, ionic, or atomic. b. CO2(s)
Problem 42
Which solid has the highest melting point? Why? C(s, diamond), Kr(s), NaCl(s), H2O(s)
Problem 43c
Which solid in each pair has the higher melting point and why?
a. TiO2(s) or HOOH(s)
b. CCl4(s) or SiCl4(s)
c. Kr(s) or Xe(s)
Problem 43d
Which solid in each pair has the higher melting point and why? d. NaCl(s) or CaO(s)
Problem 44d
Which solid in each pair has the higher melting point and why?
a. Fe(s) or CCl4(s)
b. KCl(s) or HCl(s)
c. Ti(s) or Ne(s)
d. H2O(s) or H2S(s)
Problem 53a
Classify each of the following as a component of a silicate ceramic, an oxide ceramic, or a nonoxide ceramic. a. B4C
Problem 53b
Classify each of the following as a component of a silicate ceramic, an oxide ceramic, or a nonoxide ceramic. b. Mg2SiO4
- What is the name and formula of the compound commonly used in the manufacture of glass to increase the index of refraction?
Problem 56
- What is the oxidation state of each element in the compound Ca3SiO5?
Problem 57
- What is the oxidation state of each element in the compound Mg3Si2O5(OH)4 formed by replacing aluminum ions in kaolinite with magnesium ions?
Problem 58
Problem 59
Which solid would you expect to have little or no band gap? a. Zn(s) b. Si(s) c. As(s)
Problem 60
Which solid would you expect to have the largest band gap? a. As(s) b. Sb(s) c. Bi(s)
Problem 61
How many molecular orbitals are present in the conduction band of a lithium crystal with a mass of 11.2 g?
Problem 63
A substance has a band gap of 6.9 eV at 273 K. Is this substance best classified as an insulator, a semiconductor, or a metal?
Problem 66b
Indicate if each solid forms an n-type or a p-type semiconductor.
a. silicon doped with gallium
b. germanium doped with antimony
Problem 67
Does a photon of red light with a frequency of 4.29⨉1014 Hz have sufficient energy to promote an electron from the valence band to the conduction band in a sample of silicon (the band gap in silicon is 1.11 eV)?
- What is the wavelength of light (in nm) emitted when an electron moves from the conduction band to the valence band in a sample of diamond, which has a band gap of 5.5 eV?
Problem 68
Problem 69
Teflon is an addition polymer formed from the monomer shown here. Draw the structure of the polymer.
Problem 70
Saran, the polymer used to make saran wrap, is an addition polymer formed from two monomers—vinylidene chloride and vinyl chloride. Draw the structure of the polymer. (Hint: The monomers alternate.)