化學問題 ozone

Both structures are incorrect.

The main point is that : Before bonding, O atom (1s2 2s2 2p4) has 6 electrons in its outermost shell. After bonding, O atom should have 8 electrons in its outermost shell, and this is the electronic configuration of a noble gas. Besides, since O atom does not have low-energy empty d orbitals, it cannot have more than 8 electrons in its outermost shell.


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In the first structure, the central O atom forms 1 double bond and 1 single bond, and thus has 3 non-bonding electrons in the outermost shell. It has 9 electrons in the outermost shell, and this is impossible.

To draw the correct structure, the O-O single bond should be a dative bond instead. It can be represented in two ways : O→O or +O-O-, in which the first O atom is the central atom, and the last O atom is the terminal O atom.
Now, the central O atom form a double bond and supply a pair of electrons to form a dative bond, and thus it has 2 non-bonding electrons in the outermost shell. It has now 8 electrons in the outermost shell.
In the terminal →O atom, it does not give any electrons in bond formation. It has 8 electrons in the outermost shell.
In the teminal =O atom, it forms a double bond, and thus has 4 non-bonding electrons in the outermost shell. It has also 8 electrons in the outermost shell.

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In the second structure, each O atom form two double bonds and thus has 2 non-bonding electrons in the outermost shell. Each O atom has 10 electrons in its outermost shell, and this is impossible.

The 1st one is correct but the 2nd one is wrong because oxygen cannot hold 4 bonds. The most bonds oxygen can hold are 3 and it carries a +ve charge. Besides, the 3 oxygens are NOT meant to be joined up. It really should be O-O=O but in a bent shape (like in H2O).
In fact the double bond delocalises (ie. electrons are shared and moves around). So it can be O=O-O or O-O=O or something in between.

2006-12-18 17:00:15 補充：
It is an orbital hyrbridisation concept because of delocalising electrons - can u be a bit more specific please?