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|A sample question about Lewis structures and bond
orders for some oxide ions of astatine (Z=85).
|Introducing the shorthand symbolism of "line
structures". This is not in the text.
| Line structures are a useful and very common
way of presenting Lewis structures. They are essentially
| Here are two illustrations of line structures
that look similar, but aren't quite the same.
|An application: We'll diverge
slightly and discuss bond energies and one way in which
they can be applied, the energy released (reaction
heat) in the combustion of octane. Here we get the
balanced equation for the complete combustion reaction.
(Reaction heats are not covered in the
|In order to take a look at the energy change
involved, we look at the "structures" of the
various reaction components.
|We can then calculate the net energy change when
electrons re-arrange their "allegiance", that
is, some bonds break and others form. The various bond
energies can be obtained from data bases (tables in the
text, for example)