On your own paper, let’s practice drawing Lewis structures for the following molecules. Use the periodic table to help you. Remember to follow the steps listed below.

Step 1: Add up the total valence electrons.
Step 2: Determine the central atom.
Step 3: Place non-central atoms around the central atom, and connect using lines to represent the bonds.
Step 4: Distribute remaining electrons around the non-central atoms for a full valence shell.
Step 5: Check to make sure all central atoms have a complete valence shell.
Step 6: Calculate the formal charge of each atom.

1. H₂O

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2. NH₃

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3. PO₄^3-

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4. BeH₂

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Now try these with double or triple bonds.

5. CO₂

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6. CH₂O

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7. NH₄⁺

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Now try drawing the Lewis structures for these molecules. Include all resonance structures and formal charges.

8. O₃

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9. HCO₂^-1

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10. SO₄^2-

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