The same principles apply to the water molecule, in which two lone pairs and two
bonding pairs repel each other. Again, the electron pairs have a nearly tetrahedral
arrangement, with the atoms arranged in a V shape. The angle of largest repulsion, between
the two lone pairs, is not directly measurable. However, thc lonc pair-bonding
pair (lp-bpr)e pulsion is greater than the bonding pair-bonding pair (bp-bp)r epulsion,
and as a result the H-0-H bond angle is only 104.S0, another 2.1" decrease from
the ammonia angles. The net result is that we can predict approximate molecular shapes
by assigning more space to lone electron pairs; being attracted to one nucleus rather
than two, the lone pairs are able to spread out and occupy more space.