Transcript Chapter 2

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Element
Symbol
Atom
› Electron
 Electron configuration
 Energy level (shell)
 Valence electrons
› Proton
 Atomic number
› Neutron
 Isotopes
› Nucleus
 Atomic mass
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Compound
› Formula: simple, molecular, structural
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Molecular mass
› Avogadro’s number
› mole
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Chemical equations
› Reactants
› Products
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Equations
Covalent
 Sharing electrons
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› Single bond: one pair
› Double bond: two pair
› Triple bond: three pair
Equal sharing  nonpolar bond
 Unequal sharing  polar bond
 The shape of geometric shape of a
molecule dictates its biological function
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Ionic
› Cations: + (lost electron)… think of ‘Little Atom’ joke
› Anions: - (gained electron)
Opposites attract
 Form solutions
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Especially in water (which is polar)
Solvent
Solute
Hydration
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Hydrogen bonds
› Between an atom with a partial negative
charge and a H atom covalently bonded to
oxygen or nitrogen
› Water is ‘sticky’
› Relatively weak: break and reform easily
Oxidation-reduction
 Always occur together…
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› Oxidation  loses an electron
› Reduction  gains an electron
› OIL RIG: oxidation is loss; reduction is gain
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The transfer of electrons involves the
transfer of the energy of that electron:
often occurs in living things