Monday, September 3, 2007

The Elements

Here's the latest posting on our microscopic friends. If you're especially interested, there's a good book called Nature's Building Blocks: An A-Z Guide to the Elements, by John Emsley. My previous posts on chemistry are located here.
Hope you enjoy the latest installment...

Atomic Number: 7
Atomic Symbol: N
Nitrogen gas accounts for 78% of the air we breathe, but if it rises above this level we would all die of asphyxiation. It is also a constituent of DNA and therefore an important part of the genetic code, and a key part of the amino acids that form enzymes and other proteins. Liquid ni
trogen is used to freeze blood or to preserve genetic material, such as eggs and sperm. Nitrogen is also used to make gunpowder (potassium nitrate) and dynamite (nitroglycerin).

Atomic Number: 8
Atomic Symbol: O
Oxygen is the third most abundant element in the Universe. The Earth is unusual in having a high level of oxygen gas, a sure sign of life since it's created by photosynthesis. It is well known that all animal life requires oxygen: if denied it, we start to die within three minutes. Ozone gas, which protects our planet from radiation, consists of three oxygen atoms in a V-shape. Oxygen has the ability to "oxidize" other materials: sometimes this process is rapid and intense, as in fire; other times it is slow as when oxygen turns iron into useless rust.

Atomic Number: 9
Atomic Symbol: F
From the Latin fluere, meaning to flow, the most common fluoride mineral fluorspar melts easily when heated. In humans, fluoride accumulates in the bones and teeth, making them harder and more resistant to acids. For this reason, it is added to drinking water and toothpaste. Teflon (tetrafluorethene) is used to make frying pans non-stick because it does not melt or dissolve easily in food. Fluorine gas is extremely toxic: breathing it even at tiny concentrations for a few minutes can kill.

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