Potassium Bromide, KBr, Crystallizes Like NaCl in a Face-Centered Lattice

question 20

Multiple Choice

Potassium bromide, KBr, crystallizes like NaCl in a face-centered lattice. The ionic radii of K⁺ and Br^- ions are 133 pm and 195 pm, respectively. Assuming that all Br^- ions are positioned in the face and corners of the unit cell, while the K⁺ ions are positioned along the edge alternating between anions, calculate the length of a unit cell edge.

• A) 230 pm
• B) 328 pm
• C) 523 pm
• D) 656 pm
• E) 780 pm

---

Definitions:

Nasogastric Irrigant

A solution used to flush or clear a nasogastric tube, which is a tube inserted through the nose down into the stomach.

Adult Patient

An individual receiving medical care who is beyond the age of adolescence and legally considered an adult in their respective jurisdiction.

Nasogastric (NG) Tube

A flexible tube passed through the nose into the stomach for feeding or medication delivery.

Impaired Swallowing

Difficulty in the passage of solids or liquids from the mouth to the stomach, often referred to as dysphagia.