Which of the following statements correctly describes the Lewis dot structure of the IF3 molecule?

• A. The central iodine atom has three bonding pairs and one lone pair of electrons.
• B. The central iodine atom has two bonding pairs and three lone pairs of electrons.
• C. The central iodine atom has five bonding pairs and no lone pairs of electrons.
• D. The central iodine atom has three bonding pairs and two lone pairs of electrons.

Answer: (D)

Verified step by step guidance

1. Step 1: Determine the total number of valence electrons in IF3. Iodine (I) is in group 17 and has 7 valence electrons, and each fluorine (F) atom also has 7 valence electrons. Since there are three fluorine atoms, calculate the total valence electrons as: \$7 + 3 \times 7$.
2. Step 2: Identify the central atom, which is iodine (I), and arrange the three fluorine atoms around it, forming three single bonds. Each bond represents a bonding pair of electrons shared between iodine and fluorine.
3. Step 3: Subtract the electrons used in bonding from the total valence electrons to find the remaining electrons. Each single bond uses 2 electrons, so subtract \$3 \times 2$ electrons from the total.
4. Step 4: Distribute the remaining electrons as lone pairs, first completing the octets of the fluorine atoms (each fluorine needs 6 more electrons to complete its octet after bonding). Then, assign any leftover electrons as lone pairs on the central iodine atom.
5. Step 5: Count the number of bonding pairs and lone pairs on the central iodine atom. The correct Lewis structure will show iodine with three bonding pairs (to the three fluorines) and two lone pairs of electrons, consistent with the correct answer.