---
title: "In an ionic crystal with a rock salt (\\(\\text{NaCl}\\)) lattice, anions (\\(\\text{X}^-\\)) of radius \\(r_-\\)"
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url: "https://nerd-notes.com/ubq/119223/"
date_modified: "2026-08-19T12:39:26+00:00"
---

# In an ionic crystal with a rock salt (\(\text{NaCl}\)) lattice, anions (\(\text{X}^-\)) of radius \(r_-\)

In an ionic crystal with a rock salt (\(\text{NaCl}\)) lattice, anions (\(\text{X}^-\)) of radius \(r_-\)

![A grayscale 2D square diagram representing one face of a rock salt unit cell with side length L. A legend at the top specifies: large open circles = anions (radius r-), small solid black circles = cations (radius r+). Four large open circles of equal size are located at the four corners of the square, touching along the diagonal of the square face. One small solid black circle is centered on each of the four edges of the square, touching the two adjacent corner anions. No other particles, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787143166-iO5q3Y.jpg)

- **A.** \(0.414\)
- **B.** \(0.732\)
- **C.** \(1.000\)
- **D.** \(1.414\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119223/*