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Unformatted text preview: Covalent bondingcan hold the solid together if the bonds can form a network. Examples are silicon oxide, boron nitride, silicon carbide, diamond Weak interactionshold the solid together if the covalent bonds lead to single molecule Lewis structures rather than networks. Examples are wax, naphthalene, and the sulfur eight-membered ring Borderline cases Hydrogen bonded compounds like ice and solid ammonia are somewhat molecular and somewhat network Solids can be partly crystalline and partly amorphous (polymers), or polycrystalline Solids can be partly regular and partly fluid: liquid crystals! Solids can have different interactions in different directions: graphite, mica As always, the borderline cases can be evaluated using the tradeoffs between H and TS contributions to free energy...
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- Spring '09