Gold (atomic radius = 0.144 nm) crystallises in a face-centred unit cell. What is the length of a side of the cell?
Radius, r = 0.144 nm,
Unit cell is fcc, edge of unit cell, a = ?
In face centered unit cell, diagonal of face = 4r =
[∵ face diagonal = ]
Length of side of unit cell,
a = 0.4073 nm.