Here are some examples in which the formula
suggests the arrangement:
1. the acetate ion: C2H3O2-, suggests that
- the
two Carbons stay together forming the "spine" of the molecule,
- the 3 Hydrogens stay
together as well so they are probably attached to one of Carbons
- the two Oxygens stay together and must be attached to the other Carbon.
the initial placement of bonds will looks like so:
See the full Lewis structure here.
2. hydroxylamine: can be given as NH2OH, and suggests
- NH2 most likely stays together, clearly H is/are not in the center so N
has to be,
- notice that OH stays together on the other side of the molecule.
the initial placement of bonds will looks like so:
See the full Lewis structure here.