Periodic Table Assignments

I chose astatine as my halogen because I had never heard of it before. It's name comes from the Greek word "astatos," meaning "unstable." This highly radioactive halogen was synthesized in 1940 at U.C. by bombarding bismuth with alpha particles. The total amount of astatine present in the earth's crust is less than one ounce. According to the article I read at www.periodic.lanl.gov/elements/85, the "time of flight" mass spectrometer has been used to confirm that, chemically, astatine behaves much like iodine and probably accumulates in the thyroid gland. It differs from iodine in that it is more metallic.

I chose krypton as my inert gas because I wanted to see if I could figure out the secret of Superman's heroic feats. While I continue to investigate the secrets of Superman, I will share with you what I learned about krypton.

The name "krypton" comes from the Greek word "kryptos" meaning "hidden." Krypton was discovered on May 30, 1898 by Sir William Ramsay, a Scottish chemist, and Morris M. Travers, an English chemist, while they were studying liquified air. Small amounts of liquid krypton remained after more volatile components had boiled away. Krypton comprises 0.0001% of the earth's atmosphere.

Krypton is used in some types of flashes used in high speed photography. It is combined with argon in some types of fluorescent light bulbs and with other gases to make what we would refer to as "neon" signs.

I selected tellurium as my semiconductor because its name is similar to Telluride, which makes me think of skiing, and skiing is something that we might do during the winter trimester, if we were not in class.

Tellurium is silvery-white and, in its pure form, has a metallic lustre. It is brittle and easily crushed into a powder form. Tellurium ores exist, but tellurium is a byproduct of copper refining.

Tellurium is a "p-type" semiconductor. Its conductivity increases slightly when it is exposed to light. Besides its use as a semiconduct, tellurium is added to lead to prevent corrosion, and it is also used in ceramics and for tinting glass.

Interestingly, humans exposed to miniscule amount of tellurium develop "tellurium breath," which smells like garlic.