1.3 bonding Flashcards
what is ionic bonding
electrostatic force of attraction between oppositely charged ions due to a transfer of electrons
what is covalent bonding
a shared pair of electrons
what is co-ordinate bonding
when the shared pair of electrons come from one of the atoms
what is metallic bonding
the electrostatic force of attraction between the positive metal ions and the sea of delocalised electrons
describe the bp and mp of ionic substances
high mp and bp, alot of energy required to break string electrostatic forces of attraction between oppositely charged ions
when do ionic substances conduct electricity
when molten as the ions are free to move and carry a charge
can simple covalent molecules conduct electricity
no, the electrons are not free to move
describe the mp and bp of simple covalent molecules
low mp and bp, weak vdw forces, not alot of energy is required to overcome the forces
describe the mp and bp of macromolecular molecules
high, strong and high number of covalent bonds
describe the mp and bp of metallic molecules
high, strong forces of attraction between positive metal ions and negatively charged sea of delocalised electrons
what affects the strength of metallic bonding
- number of protons/ nuclear charge
- number of delocalised electrons
- size of ion
what is electronegativity
the ability of an atom to attract the pair of electrons in a covalent bond
what affects electronegativity
nuclear charge
atomic radius
electron shielding
what are the 3 most electronegative elements
F,O,N
what are the 3 types of intermolecular forces, increasing in strength
van der waals
dipole-dipole
hydrogen bonding
van der waal forces
temporary dipoles created by the random movement of electrons, which induces a dipole.
what affects van der waals
size of molecule.
as the molecule gets larger, VDW strength gets larger.
describe dipole-dipole attraction
molecules with polar bonds have a permanent dipole.
stronger when there is a greater difference in electronegativity
describe hydrogen bonding
when F, O or N are bonded to hydrogen. there is a large difference in electronegativity.
what is the electron pair repulsion theory
the electron pairs will move to be as far away from each other as possible, to minimise the repulsive forces
shape of 2 bonding pairs and 0 lone pairs
linear, 180
shape of 2bp and 1 lp
bent, 118
shape of 3 bp and 0 lp
trigonal planar, 120
shape of 4 bp and 0lp
tetrahedral, 109.5
shape of 2bp and 2lp
bent, 104.5
shape of 5bp and 0lp
trigonal bipyramid, 90 and 120
shape of 4bp and 1lp
see saw, 89 and 119
shape of 3bp and 2bp
t shape, 89
shape 6bp and 0lp
octahedral, 90
shape of 4bp and 2lp
square planar, 90
