Complete following structures by filling in with lone pairs and double or triple bonds.

• A.
• B.
• C.
• D.

Answer: (D)

Verified step by step guidance

1. Identify the number of valence electrons for each atom in the structure. Carbon has 4, hydrogen has 1, and oxygen has 6 valence electrons.
2. For the first structure, recognize that the carbon atoms can form multiple bonds. Since there are two carbon atoms, consider forming a triple bond between them to satisfy the octet rule for each carbon.
3. For the second structure, observe the carbon-oxygen bonds. The carbonyl group (C=O) typically involves a double bond between carbon and oxygen, which satisfies the octet rule for both atoms.
4. Add lone pairs to the oxygen atoms to complete their octet. Each oxygen should have two lone pairs in addition to the bonds it forms.
5. Ensure that all hydrogen atoms are forming single bonds, as hydrogen can only form one bond to satisfy its duet rule.