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.

WEEK 11/12

How Cells Divide: Mitosis v. Meiosis

In all honestly, cell division is one of the few biology topics that does not fascinate me from a learner's perspective. Maybe I was traumatized by the memorization required on the topic by my junior high and high school teachers. The NOVA slides were great for visualization purposes, and I liked the breakdown of explanatory text with each slide. I just wish they could have used flourescent/microscopic pictures of the process like those that appear on the Wikipedia links.

Connections Between TCM and Cell Biology

Hmm. I don't have enough TCM study behind me to feel enlightened about these connections. TCM seems to focus on macrocellular levels - interrelationships between organs and systems within the body - not on the intricacies of cellular life cycles.