91Ó°ÊÓ

Associate each of the solids \(\mathrm{BN}, \mathrm{P}_{4} \mathrm{~S}_{3}, \mathrm{~Pb}\), and \(\mathrm{CaCl}_{2}\) with one of the following sets of properties. A bluish white, lustrous solid melting at \(327^{\circ} \mathrm{C} ;\) the solid is soft and malleable. A white solid melting at \(772^{\circ} \mathrm{C} ;\) the solid is an electrical nonconductor but dissolves in water to give a conducting solution. A yellowish green solid melting at \(172^{\circ} \mathrm{C}\). A very hard, colorless substance melting at about \(3000^{\circ} \mathrm{C}\).

How many atoms are there in a simple cubic unit cell of an atomic crystal in which all atoms are at lattice points?

How many atoms are there in a body-centered cubic unit cell of an atomic crystal in which all atoms are at lattice points?

Metallic iron has a body-centered cubic lattice with all atoms at lattice points and a unit cell whose edge length is \(286.6 \mathrm{pm}\). The density of iron is \(7.87 \mathrm{~g} / \mathrm{cm}^{3} .\) What is the mass of an iron atom? Compare this value with the value you obtain from the molar mass.

Nickel has a face-centered unit cell with all atoms at lattice points and an edge length of \(352.4 \mathrm{pm} .\) The density of metallic nickel is \(8.91 \mathrm{~g} / \mathrm{cm}^{3} .\) What is the mass of a nickel atom? From the atomic mass, calculate Avogadro's number.

Copper metal has a face-centered cubic structure with all atoms at lattice points and a density of \(8.93 \mathrm{~g} / \mathrm{cm}^{3}\). Its atomic mass is 63.5 amu. Calculate the edge length of the unit cell.

Barium metal has a body-centered cubic lattice with all atoms at lattice points; its density is \(3.51 \mathrm{~g} / \mathrm{cm}^{3} .\) From these data and the atomic weight, calculate the edge length of a unit cell.

11.89 Gold has cubic crystals whose unit cell has an edge length of \(407.9 \mathrm{pm}\). The density of the metal is \(19.3 \mathrm{~g} / \mathrm{cm} 3\). From these data and the atomic mass, calculate the number of gold atoms in a unit cell, assuming all atoms are at lattice points. What type of cubic lattice does gold have?

Assume X has a body-centered cubic lattice with all atoms at the lattice points. The edge length of the unit cell is \(379.0 \mathrm{pm}\). The atomic mass of \(\mathrm{X}\) is 195.0 amu. Calculate the density of \(X\).

Lead has a face-centered cubic lattice with all atoms at lattice points and a unit-cell edge length of \(495.0 \mathrm{pm} .\) Its atomic mass is 207.2 amu. What is the density of lead?