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Discovering chemistry
Discovering chemistry

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2 Lewis structures – a starting point

The theories of shared electron pairs in chemical bonding developed by G.N. Lewis may be found in a classic paper; The atom and the molecule published in the Journal of the American Chemical Society in 1916.

To illustrate this approach let’s look at two examples.

  • Are the following compounds molecular or non-molecular? Chlorine (Cl2) and sodium chloride (NaCl).

    • Chlorine (Cl2) is a molecular compound – it is made up of discrete Cl2 molecules.

    • Sodium chloride (NaCl) a non-molecular compound, is made up of Na+ and Cl- ions.

Starting with Cl2, how do two chlorine atoms form a bond to make a chlorine molecule?

You will look at simple bonding theory applied to chlorine in the next section.