electron & molecular geometry

vsepr

valence shell electron pair repulsion: electrons want to be as far away as possible

linear shape & angle

• two electron pairs

• 180 degrees

• x-a-x

trigonal planar shape & angle

• 3 & flat

• triangle like

• 120 degrees

tetrahedral shape & angle

• 4, no one pairs

• 109.5 degrees

trigonal pyramidal shape & angle

• 3 pairs

• one long pair

• 107 degrees

bent shape & angle

• two bonding pairs

• two lone pairs

  • caused by long pairs

• 104.5 degrees

  • ex. H₂O

trigonal bipyramidal shape & angle

• 5 bonding pairs

• no lone pairs

• 180, 120 & 90 degrees

seesaw shape & angle

• 4 bonding pairs

• 1 lone pair

  • ex. SF₄

t-shaped shape & angle

• 3 bonding

• 2 lone pairs

  • ex. IF₃

octahedral shape & angle

• 6 bonding pairs

• 180 & 90 degrees

  • ex. SF₆

square pyramidal shape & angle

• 5 bonding pairs

• 1 lone pair

  • ex. IF₅

square planar shape & angle

• 4 bonding pairs

• 2 unbonding pairs

  • ex. XeF₄

why do lone pairs have a greater repulsive pair than bonded ones

they occupy more space on the central atom

how can you predict if a molecule is non-polar or polar based on molecular shape

• symmetry = non-polar

• asymmetry = polar

  • check with EN values