Question

2. Face-Centered Cubic (let r = 1.00A     Show all work

A) calculation of the length of the until cell edge(a)

b) Calculation of the % void space

Answer 1

From the triangle ABC, AC2 AB2 + BC2 AC2 - a2+ a (a - edge length) AC= 2a l.e Therefore atomic radius Occupied space actual volume occupied/total voume × 4m" За 3 APF-4 substituting r = , we get, 4 Actual space- 0.74 2 Thus 74 percent of the volume of the FCC unit cell is occupied by atoms and the remaining 26 percent volume of the unit cell is vacant or void space