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.

Determine the number of atoms per unit cell for each metal.

(a) Polonium

Determine the number of atoms per unit cell for each metal.

(b) Tungsten

Determine the number of atoms per unit cell for each metal.

(c) Nickel

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.

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

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.

Barium has a density of 3.59 g/cm³ and crystallizes with the body-centered cubic unit cell. Calculate the radius of a barium atom.

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).

Identify each solid as molecular, ionic, or atomic. a. CaCl₂(s)

Identify each solid as molecular, ionic, or atomic. b. CO₂(s)

Identify each solid as molecular, ionic, or atomic. d. I₂(s)

Which solid has the highest melting point? Why? C(s, diamond), Kr(s), NaCl(s), H₂O(s)

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)

Which solid in each pair has the higher melting point and why? d. NaCl(s) or CaO(s)

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)

An oxide of rhenium crystallizes with the unit cell shown here (rhenium=gray; oxygen=red). What is the formula of the oxide?

Identify the structure of each of the two unit cells shown in Problem 48 as the rock salt structure, zinc blende structure, fluorite structure, antifluorite structure, or none of these.

Classify each of the following as a component of a silicate ceramic, an oxide ceramic, or a nonoxide ceramic. a. B₄C

Classify each of the following as a component of a silicate ceramic, an oxide ceramic, or a nonoxide ceramic. b. Mg₂SiO₄

Classify each of the following as a component of a silicate ceramic, an oxide ceramic, or a nonoxide ceramic. c. MoSi₂

Which solid would you expect to have little or no band gap? a. Zn(s) b. Si(s) c. As(s)