1.1 Lewis Structures

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The Octet Rule

Most atoms will share electrons (covalent bonding) or transfer electrons (ionic bonding) to obtain a total of 8 electrons in its valence shell.

covalent bonding
ionic bonding
1. The third row and lower can exceed the octet rule.
2. H only 2, Be only 4, B and Al only 6 (usually)
3. Molecules with odd numbers of electrons
number of valence electrons

How to Draw Lewis Structures

1. Set up skeleton with single bonds (central atom is the atom which can make the most bonds).
2. Fill the octets of the outside atoms with lone pairs of electrons.
3. Any remaining valence electrons go on central atom.
4. Once all electrons are used, form multiple bonds to the central atom if not “full.”