Choose the best Lewis structure for XeI2.

A)
B)
C)
D)
E)

A): Xe—I

B): I=X=I

C): I—Xe—I

D): Xe

E): I=Xe=I

The Correct Answer and Explanation is:

The correct answer is:
C) I—Xe—I

Explanation (300+ words):

To determine the best Lewis structure for XeI₂ (xenon diiodide), we need to follow standard steps for drawing Lewis structures and understanding the molecular geometry:

1. Count Valence Electrons:

Xenon (Xe): Group 18, has 8 valence electrons.
Iodine (I): Group 17, has 7 valence electrons, and there are 2 iodine atoms.
→ Total from Iodine: 7 × 2 = 14 electrons
Total valence electrons: 8 (Xe) + 14 (2 I) = 22 electrons

2. Determine the Skeleton:

Since xenon is the least electronegative and can expand its octet (due to available d-orbitals), it will be the central atom.

→ Skeleton: I — Xe — I

3. Distribute Electrons:

Start by connecting the atoms with single bonds: I—Xe—I
Each single bond uses 2 electrons × 2 bonds = 4 electrons
Remaining electrons: 22 − 4 = 18 electrons

Now, complete octets of the outer atoms (iodine):

Each iodine needs 6 more electrons (3 lone pairs) to complete its octet.
6 × 2 = 12 electrons for the iodines.
Remaining electrons: 18 − 12 = 6 electrons

Place the remaining 6 electrons (3 lone pairs) on the central Xe atom.

→ Xe now has 2 bonding pairs + 3 lone pairs = 10 electrons (which is acceptable since Xe can exceed the octet rule)

4. Molecular Shape and Stability:

The final Lewis structure is:

I — Xe — I
.. ..
.. Xe ..
.. ..

This gives 5 electron domains around xenon (2 bonding, 3 lone pairs), which corresponds to a linear molecular geometry (AX₂E₃) according to VSEPR theory.

Why the Other Options Are Incorrect:

A): Just Xe—I (incomplete, missing one I)
B): I=X=I suggests double bonds, which are incorrect and violate iodine’s typical bonding pattern
D): Just Xe (no bonding shown)
E): I=Xe=I suggests double bonds again, which is incorrect

Conclusion:

Option C (I—Xe—I) is the best Lewis structure for XeI₂, showing proper bonding, lone pairs, and satisfying octet/expanded octet rules.