Shapes of molecules

4 bonding regions, no lone pairs (name and angle)

Tetrahedral, 109.5

3 bonding regions, 1 lone pair (name and angle)

Pyramidal, 107

2 bonding regions, 2 lone pairs (name and angle)

non-linear, 104.5

2 bonding regions, no lone pairs (name and angle)

linear, 180

3 bonding regions, no lone pairs (name and angle)

trigonal planar, 120

6 bonding regions, no lone pairs (name and angle)

octahedral, 90

4 bonding regions, 2 lone pairs (name and angle)

square planar, 90

5 bonding regions, no lone pairs (name and angle)

trigonal bipyramidal, 90 and 120

why do lone pairs make the bond angle smaller?

lone pairs repel more than bonded pairs

why do lone pairs repel more than bonded pairs?

lone pairs are closer to the nucleus

why are bonded atoms held in a definite shape?

the arrangement of electron pairs minimises repulsion

define bond angle

the angle between the bonded pairs of electrons

how much is the bond angle reduced for each lone pair?

2.5 degrees