Chapter 16, Problem 2ASA

In an FCC structure, the atoms are found on the corners of the cubic unit cell and at the center of each face. The unit cell has an edge whose length is the distance from the center of one corner atom to the center of another corner atom on the same edge. The atoms on the diagonal of any face are touching. One of the faces of the unit cell is shown below in the following:

a. Show the distance $d_{\text{O}}$ on the sketch. Draw the boundaries of the unit cell.

b. What is the relationship between the length of the face diagonal and the radius of the atoms in the cell?

Face diagonal $=$ ______________

c. How is the radius of the atoms related to $d_{\text{O}}$?

$r=$ ______________

d. Silver metal crystals have an FCC structure. The unit cell edge in silver is $0.4086\text{nm}$ long. What is the radius of a silver atom?

______________ $\text{nm}$