Window on the Solid State Report Form

Please read these instructions first. Answer the following questions in the space provided. Once all of the questions are answered, click on the "Write Report" button at the bottom of the page. A new page will load in your browser that contains your answers. Print this new page. You may save this report to disk after clicking on the "Write Report" button and your answers are displayed as part of the web page. The printed copy of your report is the only record of your work, therefore do not lose it. This form MUST be completed on the web. You will not be able to use this web form if you save on a disk and try to use it while not accessing the web server.

Part I: Structures of Metals

Question 1. The element Ru crystallizes with a hexagonal closest packed structure.

A. How many other atoms are nearest neighbors to a single Ru atom?

B. In the crystal lattice of Ru there are layers in which atoms are closest packed in two dimensions. Draw and describe the arrangement of atoms in such a layer. There will be space on the report form for you to draw and describe the arrangement of atoms in a two dimensional closest paced arrangement.

The three-dimensional structure is represented by stacking these layers. As layers in the structure are built up, which layer (2, 3, 4, etc.) is the next to have its atoms aligned directly over those in layer 1?

Question 2. Name an element that crystallizes in a simple cubic structure. What is the coordination number of each atom in this structure?

Element:
Coordination number of each atom:

Part II: Unit Cells of Metals

Question 3. Draw a two-dimensional array of dots representing lattice points in a crystal. Outline two possible unit cells and show their unit-cell vectors.

The following two-dimensional array of dots representing lattice points will be printed on your report for you. On the printed array, outline two different possible unit cells and show their unit-cell vectors.

Question 4. Define TWO of the terms below.

Term	Definition
crystalline solid
lattice points
x-ray diffraction
unit cell
identical points

Question 5. Iron forms a body-centered cubic crystal. If the length of a unit cell edge is 287 pm, what is the radius of an iron atom?

Radius of an iron atom: pm

Question 6. How many atoms (counting only the part of each atom that is actually inside the unit cell) are in one unit cell of a face-centered cubic lattice? Show clearly how you arrived at this result.

Number of atoms in one unit cell of a face-centered cubic lattice:

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