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Step-wise Procedure
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Write the skeletal
structure (which atoms are bonded?).
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Count all valence
electrons (in pairs).
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Place one pair of
electrons in each bond.
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Complete the octets
of the terminal atoms.
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Put any remaining
electron pairs on the central atom, or ....
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Use multiple bonds
if needed to complete the octet of the central atom.
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Show formal charges
and resonance forms as needed.
Apply the OCTET RULE as follows:
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H never has more
than 2 electrons (i.e., only one bond).
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2nd row elements
(e.g., C, N, O) almost always have an octet and never
have more than 8 electrons (sometimes Boron has only 6)
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3rd row and higher
elements can have more than 8 electrons but only after the octets
of any 2nd row elements are completed.
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