covalent bonds

exceptions to the octet rule

incomplete

• H: stable w/ 2 e^-s

• He: stable w/ 2 e^-s

• Be: 4

• B: 6

expanded octet

• period 3 and below because it has access to the D sublevels which allows it to obtain more electrons

  • EX. P: 10

  • S: 12

VSEPR shape: 2 electron groups

linear, 180

VSEPR shape: 3 electron groups

trigonal planar, 120

bent, 120

VSEPR shape: 4 electron groups

tetrahedral, 109.5

trigonal pyramidal, 109.5

bent, 109.5

bond polarity table

0.0 - 0.4 covalent (non-polar)

0.4 - 1.0 covalent (moderately polar)

1.0 - 2.0 covalent (very polar)

≥ 2.0 ionic

molecular polarity

whether a molecule has an overall separation of electric charge, resulting in a molecule with a positive end and a negative endbased on the arrangement of its polar bonds and the shape of the molecule

qualities of a polar molecule

molecules that have an uneven distribution of charge across their geometry resulting in one side being positive and the other side negative

qualities of a non-polar molecule

molecules that have an even distribution of charge, resulting in no distinct positive or negative ends.