unit 1.4 bonding

Cards (15)

ionic bonding
the electrostatic attraction between oppositley charged ions
e.g. $Na^+$ $Cl^-$
covalent
formed by a shared pair of electrons
co-ordinate bond
shared pair of electrons which has been provided by one of the bonded atoms only
electronegativity
relative tendency of an atom to attract an electron pair in a covalent bond
most electronegative
fluorine
dipole
a permanent dipole is a small charge difference across the bond that is a result from difference in electronegativities of the bonded atom
example of permanent dipole
polar covalent
induced dipole
uneven distribution of electrons ~
polar molecules
has lone pairs of electrons around the central atom
van der waals
weak forces between dipoles
example of van der waals
chlorine 30 electrons
iodine 106 electrons - stronger
hydrogen bonds
forces between a lone pair of electrons on a N, O or an F and a H $\delta$ + on a neighbouring molecule
stronger than van der waals
VSEPR- valance shell electron pair repulsion theory
gives an understanding of the 30 shapes of molecules and why they occur
lone pairs
repell more than unbonded ones
molecules with hydrogen bonding
more energy needed to overcome forces of attraction since hydrogen bonds are stronger than van der waals