Assignment 6

1. My Halogen of the Week

Along with fluorine, bromine, iodine and astatine, chlorine is a member of the halogen series that forms the group 17 of the periodic table - most reactive group of elements. It combines readily with nearly all elements. Chlorine is a member of the salt-forming halogen series and is extracted from chlorides through oxidation often by electrolysis. With metals, it forms salts called chlorides. As the chloride ion, Cl−, it is also the most abundant dissolved ion in ocean water.

The symbol for chlorine is Cl. As the chloride ion it is abundant in nature and necessary to most forms of life, including humans. In its common elemental form (Cl2 or "dichlorine"), it is a pale green gas about 2.5 times as dense as air. It has a disagreeable, suffocating odor that is detectable in low concentrations and is choking and poisonous. Chlorine is a powerful oxidant and is used in bleaching and disinfectants. As a common disinfectant, chlorine compounds are used in swimming pools to keep them clean and sanitary. Chlorine-containing molecules have been implicated in the destruction of the ozone layer.

2. Alchemy: Science, Magic, Art or all three?

I think it's all three. There is something wonderfully magical about converting one substance into another. The early alchemists were transforming substances before they had the tools and practices to know what they were doing from a scientific point of view. They were naturally dabbling in mysticism and magic at this point in their discoveries. They employed trial and error (which I think of as an "art") until they got it right. As they got more sophisticated, certain scientific principles became evident. Modern-day alchemy, while much more sophisticated, is still a process of "trial and error" and "art". It is definitely "scientific".

3. A Short Introduction to Chinese Alchemy

Wow! This is a very interesting web site. Thank you, Larry, for introducing me to it. I've never studied alchemy, or even done much reading about Daoism, but I’ve recently taken an interest in the latter. Just this week, I did a presentation in one of my classes on the history of Qi Gong which, as you know, is steeped in Daoist philosophy.

I found this web site really fascinating, and very deep. It is amazing to me how sophisticated they were at that time.