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Solid State. Solids. Solids can be classified as crystalline solids (highly regular arrangement of atoms or ions or molecules) represented by a lattice. Unit cell = smallest repeating unit of a lattice Cubic, body centered, face centered or as amorphous solids (structural disorder) like glass.
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Solids • Solids can be classified as crystalline solids (highly regular arrangement of atoms or ions or molecules) represented by a lattice. • Unit cell = smallest repeating unit of a lattice • Cubic, body centered, face centered • or as amorphous solids (structural disorder) like glass
Morton Salt (p 29) • A chemical (CaSiO3) called a desiccant is added to table salt (NaCl) to prevent water absorption and caking. • CaSiO3 + H2O 3CaO∙2SiO2 ∙3H2O ≡ hydrate • Here is another example: CoCl2 (cobalt chloride anhydrous, blue); CoCl2∙2H2O (cobalt chloride dihydrate, purple); Co(H2O)6)Cl2 (hexaaquacobalt(II) chloride, pink)
Desiccants (p 30) • Desiccants or drying agents act as a sink for water (hygroscopic) to protect the integrity of a product (salt, electronics, shoes, ). • Desiccant efficiency is measured by mass of water stored per mass of desiccant. • When added to food, they must be chemically stable, non toxic and able to absorb a lot of water per unit weight of desiccant
Diamond • Diamond is a form of elemental carbon, produced under high P and T. • Exceptional hardness (e.g. diamond drill; hardest natural mineral), lustre (e.g. jewelry), clarity. • Diamond does not conduct electricity.
Diamond has 2 interpenetrating fcc lattices. • Isometric hexoctahedral crystal.
Diamond Color • Diamonds made of pure carbon are transparent, but if there are impurities, i.e. other atoms substitute for C or structural defects the diamond becomes colored.
Another form of Carbon • Graphite (Greek for to write or draw) is another form of carbon and is used as pencil “lead”. • It is the most stable form of C at room T and P. • Graphite conducts electricity.
Graphite • Hexagonal arrangement of C atoms form layers that give graphite its lubricating property.