Classify each of the following materials as falling into one of the categories listed in Table 12.2. What particles make up these solids, and what are the forces of attraction between particles? Give one physical property of each.
(a) Si doped with P
(b) Graphite
(c) Benzoic acid, C₆H₅CO₂H
(d) Na₂SO₄

Data given in Table 12.2

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TABLE 12.2 Structures and Properties of Various Types of Solid Substances Forces Holding Units Together Type Ionic Metallic Molecular Examples NaCl, K₂SO4, CaCl2, (NH4)3PO4 Iron, silver, copper, other metals Alloy H₂, 02, 12, H₂O, CO2, CH4, CH3OH, CH3CO₂H Network Graphite, diamond, quartz, feldspars, mica Amorphous Glass, polyethylene, nylon Sterling silver, bronze, brass Structural Units Positive and negative ions; no discrete molecules Metal atoms (positive metal ions with delocalized electrons) Molecules Atoms held in an extended two- or three- dimensional network Covalently bonded networks with no long- range regularity Lattice of metal atoms with other metal atoms in the lattice (interstitial or substitutional) Ionic; attractions among charges on positive and negative ions Metallic; electrostatic attraction among metal ions and electrons London dispersion forces, dipole-dipole forces, hydrogen bonds Covalent; directional electron-pair bonds Covalent; directional electron-pair bonds Metallic Typical Properties Hard; brittle; high melting point; poor electric conductivity as solid, good as liquid; often water-soluble Malleable; ductile; good electric conductivity in solid and liquid; good heat conductivity; wide range of hardness and melting points Low to moderate melting points and boiling points; soft; poor electric conductivity in solid and liquid Wide range of hardness and melting points (three-dimensional bonding > two-dimensional bonding); poor electric conductivity, with some exceptions Noncrystalline; wide temperature range for melting; poor electric conductivity, with some exceptions Wide range of physical and electrical properties. Can be homogeneous or heterogeneous mixtures or intermetallic compounds.