Which of the following statements correctly describes the Lewis dot structure for the IO_2^- ion?

• A. The central iodine atom is surrounded by two oxygen atoms, each connected by a single bond, and the iodine atom has one lone pair; the overall structure carries a -1 charge.
• B. The central iodine atom is surrounded by two oxygen atoms, each connected by a double bond, and the iodine atom has no lone pairs; the overall structure carries a -2 charge.
• C. The IO_2^- ion has a linear structure with iodine bonded to two oxygen atoms by triple bonds.
• D. The Lewis structure for IO_2^- consists of iodine bonded to one oxygen atom and one lone pair, with no formal charge.

Answer: (A)

Verified step by step guidance

1. Step 1: Determine the total number of valence electrons for the IO_2^- ion. Iodine (I) has 7 valence electrons, each oxygen (O) has 6 valence electrons, and the negative charge adds 1 extra electron. So, total valence electrons = 7 + 2 × 6 + 1.
2. Step 2: Draw a skeletal structure with iodine as the central atom bonded to two oxygen atoms. Connect iodine to each oxygen with single bonds initially.
3. Step 3: Distribute the remaining valence electrons to satisfy the octet rule for the oxygen atoms first, then place any leftover electrons on the iodine atom as lone pairs.
4. Step 4: Check the formal charges on each atom using the formula: \(\text{Formal charge} = \text{Valence electrons} - (\text{Nonbonding electrons} + \frac{1}{2} \times \text{Bonding electrons})\). Adjust bonding (single or double bonds) if necessary to minimize formal charges and match the overall charge of -1.
5. Step 5: Analyze the resulting Lewis structure to confirm that iodine has one lone pair, each oxygen is connected by a single bond, and the overall ion carries a -1 charge, which matches the correct description.