what scale is used to measure electronegativity
the pauling scale
using the pauling scale, compare the electronegativities of F and H
F -> 4.0
H -> 2.2
4.0 - 2.2 = 1.8
define electronegativity
The ability of an atom to attract the bonding electrons in a covalent bond to itself
what happens to electronegativity across a period
it increases
what happens to electronegativity up a group
it increases
how can electronegativity cause bond polarity
If two atoms have different electronegativities, the more electronegative atom pulls the bonding electrons closer to itself, making the bond polar
what happens to the less electronegative atom
it becomes δ+ (slightly positive)
what happens to the more electronegative atom
The more electronegative atom becomes δ- (slightly negative)
how can electronegativity predict the scale of bond polarity
the larger the difference in electronegativity between the two atoms, the greater the bond polarity
what two factors does the overall polarity of a molecule depend on
-the polarity of its individual bonds
-the shape of the molecule
how can the shape of a molecule affect the overall polarity of a molecule
-if polar bonds point in opposite directions, they cancel each other out, making the molecule non-polar
-if the polar bonds roughly point in the same direction, the molecule is polar
give an example using CO2
CO2 has two polar C=O bonds but they point in opposite directions, cancelling each other out and making the molecule non-polar overall
