Thursday, October 11, 2007

The Elements

It's been a while since I've posted about our sub-atomic friends, the atoms that make up our world. There's an excellent reference book on the subject called Nature's Building Blocks: An A-Z Guide to the Elements, by John Emsley. This and several other books are the basis for the Hansisgreat chemistry posts. If you'd like to check out the previous chemistry posts, click here.
Chemistry may seem like a geek pursuit, but I believe it's good to be a well-rounded, informed person. So it's good to know a little bit about...

Neon:
Atomic Symbol: Ne
Atomic Number: 10
Neon is a colorless, odorless gas which is unreactive towards all known ch
emicals. It was discovered in 1898 by William Ramsay and Morris Travers. A rival chemist, J. Norman Collie, also laid claim to the discovery of neon. Although this assertion is suspect, Collie was an accomplished chemist and is reputed to have been the character on whom Conan Doyle based his fictional detective Sherlock Holmes.
Neon is used mainly in so-called neon signs, although only the red ones are made with pure neon. They are quite robust, operating without attention for up to 20 years.

Sodium:
Atomic Symbol: Na
Atomic Number: 11
The chemical symbol, Na, comes from the Latin name natrium. Sodium has been known since ancient times, mostly in the form of salt (NaCl, sodium chloride). Sodium is essential for all animal life. Most people who eat meat, however, get more than enough sodium from this source. Prehistoric man discovered that animals needed salt licks to survive in captivity. Sodium has been leaching from the earth's soil and rocks into its oceans for billions of years. As a result, only 4% of the planet's water is "fresh", the rest is salt water.

Magnesium:
Atomic Symbol: Mg
Atomic Number: 12
Magnesium is a silvery-white, relatively soft metal which burns when ignited and it reacts with hot water. Humans need at least 200 milligrams each day, but a normal diet provides more than enough. Magnesium is often used by car manufacturers because of its environmental benefits in making vehicles lighter and longer-lasting. Reducing the weight of a car means not only that it uses less fuel but also that it causes less damage in accidents.
The Earth's mantle (the layer beneath the crust) is composed of magnesium silicates, making it the third most abundant element in the planet. Since it burns with very bright light, it is used in incendiary bombs, flash bulbs, and rescue flares.

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