Zusammenfassung der Ressource
2.2 Intermediate Bonding and
Bond Polarity
- Electronegativity
- The measure of attraction of an atom in a
molecule for a pair of electrons in a
covalent bond
- The Pauling Scale- electronegativity increases
across a period and down a group, making flourine
the most electronegative element
- Ionic and Covalent bonding
- They are the extremes of a continuum
of bonding type
- To find what degree a bond in a molecule is covalent
or ionic, find the difference in electronegativity then
use a table to find the result
- Less electronegative is covalent,
more elctronegative is ionic
- Polar bonds
- The more electronegative
element atom attracts the
electron pair more so it will
have a delta negative charge
whilst the other atom has a
lesser share of the elctron
pair so has a delta positive
charge.
- A covalent bond in which there is a
separation of charge (one end delta negative
and the other delta positive)
- Can only form between two different molecules as two of
the same molecules have the same amount of
electronegativity so the electron charge is in the middle
- The more electronegative a molecule, the
more the elctron pair will move towards it,
making it more ionic than covalent
- Polar molecules
- Just because a molecule has polar bonds, it
doesn't mean that it a polar molecule
- Lacks symmetry, is linear, has a single H
atom, has an OH at one end, has an end at
one end.
- Uneven distribution of charge- if negative is on
the outside and positive on the inside then the
molecule will not be polar
- Non-polar molecule
- Symmetrical, an element or a carbon compound