Chemical Bonding + Structure

• electrostatic attraction between oppositivley charged ions • transfer of electrons • polarity difference greater than 1.7 • usually metal + non metal (cations and anions)

• electrostatic attraction between a pair of electrons and a positively charged nuclei • sharing of electrons • usually nonmetal+ nonmetal

• negatively charged metal ions are attracted to delocalized electrons • metal + metal

are formed when electrons are transferred from one atom to another to form ions with complete outer shells of electrons - consist of ions held tightly together in attic structures by ionic bonds

ions containing more than one elements

metals LOSE electrons to form positive ions

non-metals gain electrons to form negative ions

accorrding to position on periodic table - transition metals can form more than one charge

• solids • lattice structure • high melting point + boiling point • low volatility • do NOT conduct electricity in solid state • soluble in water • neutrally charged due to balance of positive and negative ions

octet rule/stability: to achieve a full shell of valance electrons

a group of atoms held together by covalent bonds

bond length decreases and bond strength increases

the tendency of an atom in a molecule to attracted a shared pair of electrons towards itself

polar bonds form when two atoms bonded together have different electronegativity values (UNEQUAL SHARING)

VALANCE SHELL ELECTRON PAIR REPULSION: the total # of electron domains determine the geometrical arrangement by maximum repulsion • ELECTRONS ARRANGE THEMSELVES AROUND A CENTRAL ATOM SO THA THEY ARE AS FAR APART AS POSSIBLE

electron domains: 2 (2 atoms bonded to central atom) angle: 180

electron domain: 3 (2 atoms bonded to central atom with one or two un paired electrons) angle: 105

electron domain: 3 ( 3 atoms bonded to central atom) angle: 120

electron domain: 4 (3 atoms and an unbonded pair bonded to central atom) angle: 107 or less than 109.5

electron domain: 4 (4 atoms bonded to central atom) angle: 109.5

symmetrically also is taken into account

the physical properties of molecular substances that result from different type of forces between their molecules

• van der waal forces • london forces (dispersion forces) • dipole-dipole forces • hydrogen bonding

• temporary dipoles due to fluctuating electrical field • electrons can be unevenly spread which lead stop temporary dipoles trend: increase with increasing molecular mass