polarity

bond polarity

• when electrons are unequally shared by 2 bonded atoms leading to a negative and a positive end

• uneven distribution of electrons inside a bond contributes to the creation of an electric dipole. we determine which atom will attract more electron density from the table of electron negativities. bonds polarity can fall between non polar to completely polar

non polar covalent bond

• type of chemical bond formed when electrons are shared equally between 2 atoms

• the diatomic hydrogen molecules bond between the hydrogen atoms

polar covalent bond

• atoms with high values of electron negativity exert higher ability to attract electrons that atoms with lower values of electron negativity

• leading to unequal sharing of electrons which will be drawn closer the higher the electronegative atom

bond dipole moment

• used to determine the polarity of a chemical bond with a molecule

• used when there is a separation of positive and negative charges on banded atoms due to their unequal attraction for the bonded electrons

consequences of bond dipole moment

• atoms with high values of electronegativity exert a higher ability to attract electronic then atoms with lower, greater difference greater dipole

polar molecule

• to establish wether a molecule is polar we carry out an experiment

• attract a tug boat along each polar bond with pulling strengths reflecting the bond polarities

• if molecules move as a result of the imbalance in forces when the molecule is polar

London forces

• exist between all types of molecules and arises from fluctuations in electron clouds

• forces become stranger as rhetoric masses of the atoms in the molecules increases the number of atoms in the molecule increases so the number of atoms in the molecules increases so London forces depend on the types and total number of atoms

dipole-dipole forces

• exist between polar molecules and increase in strength s the dipole moment of the molecules increases

• In a polar liquid, the molecules attempt to align themselves so that the +ve end of the molecule is aligned with the –ve end of a neighbouring molecule, thereby causing attraction

• Their attempts to do this are being
  continually disrupted by the thermal motion (jostling) of the molecules in the liquid, so they only achieve this
  alignment to a small extent

hydrogen bonding

• Intermolecular force arises when the molecules contain any O-H, N-H or F-H bonds. This is called HYDROGEN-BONDING and involves the interaction of a lone-pair of electrons on O, N or F with an H attached to O, N or F on
  a neighbouring molecule

• This is because O-H, N-H and F-H bonds are highly polar, to an extent that directed interactions occur between the neighbouring
  molecules