1.    Tells us 4 regions Tells us 3 regions As shown in Lewis diagrams above:  There are 4 regions of electron density around the S in SCl 2 2(S-Cl) and two lone pairs of electrons  These four regions repel each other to gain maximum stability. This results in the 109 0 bond angle observed.  There are 3 regions of electron density around the O in O 3 (1 O-O), 1(O=O) and one lone pair of electrons.  These three regions repel each other to gain maximum stability. This results in the 120 0 bond angle observed.