Aluminum (Al) crystallizes as a face-centered unit cell with an edge length of 404 pm. What is the atomic radius of aluminum?
A) 143 pm
B) 202 pm
C) 286 pm
D) 175 pm
E) 808 pm

Question

Quizplus · Accepted Answer

In a face-centered cubic (FCC) unit cell, the atomic radius (r) is related to the edge length (a) by the formula: a = 2√2r. For aluminum, a = 404 pm. Solving for r gives r = a / (2√2) = 404 pm / (2√2) ≈ 143 pm.

Aluminum (Al) Crystallizes as a Face-Centered Unit Cell with an Edge