2.  Element  Symbol  Atom › Electron  Electron configuration  Energy level (shell)  Valence electrons › Proton  Atomic number › Neutron  Isotopes › Nucleus  Atomic mass

3.  Compound › Formula: simple, molecular, structural  Molecular mass › Avogadro’s number › mole  Chemical equations › Reactants › Products  Equations

4.  Covalent  Sharing electrons › 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

5.  Ionic › Cations: + (lost electron)… think of ‘Little Atom’ joke › Anions: - (gained electron)  Opposites attract  Form solutions › Especially in water (which is polar) › Solvent › Solute › Hydration

6.  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

7.  Oxidation-reduction  Always occur together… › Oxidation  loses an electron › Reduction  gains an electron › OIL RIG : o xidation i s l oss; r eduction i s g ain  The transfer of electrons involves the transfer of the energy of that electron: often occurs in living things