---
title: "The table below summarizes structural information for the triiodide ion, \\(\\text{I}_3^-\\), and iodine trifluoride, \\(\\text{IF}_3\\).  | Species | Total valence electrons | Bonding pairs on central atom | Lone pairs on central atom | |—|—|—|—| | \\(\\text{I}_3^-\\) | \\(22\\) | \\(2\\) | \\(3\\) | | \\(\\text{IF}_3\\) | \\(28\\) | \\(3\\) | \\(2\\) |  Based on VSEPR theory and the electron domain geometry of each species, which of the following correctly identifies their molecular geometries and provides the correct justification for the arrangement of the electron domains?"
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url: "https://nerd-notes.com/ubq/123475/"
date_modified: "2026-09-28T11:59:52+00:00"
---

# The table below summarizes structural information for the triiodide ion, \(\text{I}_3^-\), and iodine trifluoride, \(\text{IF}_3\).

| Species | Total valence electrons | Bonding pairs on central atom | Lone pairs on central atom |
|—|—|—|—|
| \(\text{I}_3^-\) | \(22\) | \(2\) | \(3\) |
| \(\text{IF}_3\) | \(28\) | \(3\) | \(2\) |

Based on VSEPR theory and the electron domain geometry of each species, which of the following correctly identifies their molecular geometries and provides the correct justification for the arrangement of the electron domains?

The table below summarizes structural information for the triiodide ion, \(\text{I}_3^-\), and iodine trifluoride, \(\text{IF}_3\).

| Species | Total valence electrons | Bonding pairs on central atom | Lone pairs on central atom |
|---|---|---|---|
| \(\text{I}_3^-\) | \(22\) | \(2\) | \(3\) |
| \(\text{IF}_3\) | \(28\) | \(3\) | \(2\) |

Based on VSEPR theory and the electron domain geometry of each species, which of the following correctly identifies their molecular geometries and provides the correct justification for the arrangement of the electron domains?

- **A.** \(\text{I}_3^-\) is bent and \(\text{IF}_3\) is trigonal planar because electron-pair repulsion is minimized when nonbonding electron pairs occupy axial positions.
- **B.** \(\text{I}_3^-\) is linear and \(\text{IF}_3\) is trigonal pyramidal because nonbonding electron pairs occupy axial positions to minimize repulsions with equatorial bonding pairs.
- **C.** \(\text{I}_3^-\) is linear and \(\text{IF}_3\) is T-shaped because nonbonding electron pairs occupy equatorial positions to minimize \(90^\circ\) electron repulsions.
- **D.** \(\text{I}_3^-\) is linear and \(\text{IF}_3\) is T-shaped because nonbonding electron pairs occupy axial positions to maximize the distance between the terminal atoms.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123475/*