1) Nickel has a unit cell that is a face-centered cubic with a volume of 43.763 Å3. The atom at the center of each face just touches the atoms at the corners. What is the atomic radius of nickel?
(a) 0.881 Å
(b) 1.246 Å
(c) 2.492 Å
(d) 1.661 Å
(e) 0.831 Å
2) Cadmium oxide has a unit cell that is a face-centered cubic. The ionic radius of Cd2+ is 0.97 Å and the ionic radius of O2- is 1.32 Å. What is the density of CdO?
(a) 1.3 x 1024 g/cm3
(b) 8.9 g/cm3
(c) 2.2 g/cm3
(d) 8.9 x 10-24 g/cm3
(e) 13 g/cm3
3) Which of these substances has the lowest melting point?
(a) LiBr
(b) CaO
(c) CO
(d) CH3OH
4) Cesium chloride has a unit cell that is a body-centered cubic and sodium chloride has a unit cell that is a face-centered cubic. Which of the following accounts for this difference?
(a) the lower electronegativity of the cesium atom
(b) the larger radius of the cesium ion
(c) the higher charge on the cesium nucleus
(d) the lower ionization energy of the valence electrons found in cesium
5) Which of the following is the most important factor affecting the unit cell structure of an ionic compound?
(a) the radius ratio of the ions
(b) the atomic mass of the ions
(c) the charge on the ions
(d) the rate at which crystallization occurs
6) Palladium has a unit cell that is a face-centered cubic. If the density of palladium is 12.0 g/cm3 at 25°C, what is its radius?
(a) 0.107 nm
(b) 138 pm
(c) 152 pm
(d) 1.96 x 10-8 nm
(e) 1.96 x 10-8 cm
7) The length of a unit cell for an atom of gold is 407.9 pm. If the density of gold is 19.3 g/cm3, what type of cubic lattice does gold have?
(a) simple or primitive cubic
(b) body-centered cubic
(c) face-centered cubic
8) Silver has a unit cell that is a face-centered cubic and a density of 10.50 g/cm3. Using this data, calculate Avogadro's number.
(a) 6.02 x 1023