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Date: 30-10-2020
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Date: 17-4-2019
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Date: 5-4-2019
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Fig. 1.1: Lewis dot structure of ozone.
In figure 1.1 we see that the Lewis Dot Structure of Ozone has a dobule bond between the left and center oxygens, and a single between the right and center. But we could have written as in figure 1.2, where we switched the double and single bonds.
Fig. 1.2: another valid Lewis dot structure of ozone
So which of the above two structures is the correct one that accurately describes ozone?
Neither, as both bonds are between oxygen and oxygen, and so should be of the same length. That is, if you think about it, a double bond should be shorter than a single bond. There are two facets of logic to this. First, the double bond is stronger, because if you break the double bond, you end up with the single bond. Second, the stronger the bond attraction, the closer the nuclei, and so the stronger double bond will be shorter than the weaker single bond. But the bonds are between identical atoms with identical connectivity, and so they should be the same length. So we introduce the concept of Resonance, and the above two structures are actually resonance structures, with the real structure being a mixture of the two (you could say that bond is not single or double, but 1.5).
Fig. 1.3: The two resonance structures for ozone. Note the two headed arrow represents resonance structures, and neither of these is the actual molecule, with the real molecule being the mixture of these two structures.
In reality, what we will learn in chapter 9 is that the second bond of the double bond, which is called a π
bond, is not between two atoms, but between all three. That is, the failure of the Lewid dot structure is in the concept that a bond is an orbital shared by two atoms, where in this case it is shared by three atoms. This could be expressed by the dotted line in figure 1.4
Fig. 1.4: Ignoring the lone electrons, this images is showing that the bonding electron on the dotted orbital is actually being shared by all three atoms.
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اكتشاف تأثير صحي مزدوج لتلوث الهواء على البالغين في منتصف العمر
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زهور برية شائعة لتر ميم الأعصاب التالفة
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المجمع العلمي يواصل دورة إعداد أساتذة قرآنيّين في النجف الأشرف
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العتبة العباسية المقدسة توزع معونات غذائية في الديوانية
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قسم الشؤون الفكرية يبحث سبل التعاون المشترك مع مؤسَّسة الدليل للدراسات والبحوث
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قسم العلاقات العامة ينظّم برنامجًا ثقافيًّا لوفد من جامعة الكوفة
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