Platinum has a face-centered cubic crystal structure and a density of 21.5 g/cm³. What is the radius of the platinum atom A) 69 pm B) 98 pm C) 139 pm D) 196 pm E) 277 pm

Question

Quizplus · Accepted Answer

The face-centered cubic (FCC) structure has a relation between the atomic radius (r) and the edge length (a) of the unit cell: a = 2√2r. Using the density and molar mass of platinum, we can calculate the volume of the unit cell and then find the edge length. From there, we can solve for the atomic radius, which is approximately 139 pm.

Platinum Has a Face-Centered Cubic Crystal Structure and a Density