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Chem 124
Dr. Neff
KEY to Solid State Chemistry Workbook
You will be responsible for ALL the solid state material on Exam 3.
1.
Find the repeating
square unit cells
in each of the following patterns.
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Dr. Neff
2.
2.
In each of the cases shown below, draw zdiagrams for the unit cells shown and determine the
net number of atoms per unit cell.
a) Nickel, as well as many other metals, crystallizes in the structure shown below
4 net atoms, from 8 x 1/8 + 6 x 1/2
b) Polonium is the only element known to crystallize in the structure shown below.
1 net atoms, from 8 x 1/8
c)
Iron, as well as many other metals, crystallizes in the structure shown below
2 net atoms, from 8 x 1/8 + 1
d.
Shown in the figure below is the unit cell structure for one form of C, the diamond structure.
Also
shown is the corresponding zdiagram for this unit cell.
Using this zdiagram, determine the
contribution of atoms to each zlayer, and from this, determine the net number of atoms contained
within one unit cell.
z = 0, 1
z = 0.5
Chem 124
Dr. Neff
In z = 0,1, see a net contribution of 2 atoms
In z = 0.25 there are 2 atoms completely in cell
In z = 0.5, there are 4 atoms each 1/2 in the cell so 4 x 1/2 = 2
z = 0.75 is just like z = 0.25, so there are 2 atoms completely in cell
There are 8 net atoms in this unit cell
3.
Find the simplest formula for the following unit cell structure.
Put the “elements” in the formula in
alphabetical order.
z=0, 1
z= 0.25
z = 0.5
z = 0.75
KEY:
A
2 atoms in body of unit cell
B
4 x 1/8 + 6 x ¼
= 2
C
2 x ½ + 1 = 2
A
2
B
2
C
2
which reduces to ABC
4.
a)
Draw a set of zdiagrams for a unit cell having the hypothetical formula M
2
N.
Be sure that the
unit cell is a cubic variant and has a regular structure.
Remember that the bottom (z = 0) and top (z =
1) layers must be the same.
Note that there is probably more than one way to draw zdiagrams to
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This note was uploaded on 02/10/2009 for the course CHEM 124 taught by Professor Hascall during the Spring '08 term at Cal Poly.
 Spring '08
 Hascall
 Chemistry

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