Phosphorus - Phosphorus

Japanese: リン(燐) - りん

Its atomic symbol is P. Its atomic number is 15 and its atomic weight is 30.973761998. It is a nonmetallic element. It was discovered in urine by Brandt in 1669. There are more than 10 allotropes, including white phosphorus, purple phosphorus, and black phosphorus, but they have not been fully elucidated. Generally, amorphous or crystalline red phosphorus and yellow phosphorus, which is white phosphorus with a red phosphorus film on its surface, are known. White phosphorus is a colorless crystal with a density of 1.82, a melting point of 44.2°C, and a boiling point of 280.5°C. Purple phosphorus is a purple crystal with a specific gravity of 2.35, a melting point of 589.5°C (at 43.1 atm), and a sublimation point of 416°C. Black phosphorus is a metallic, lustrous iron-gray crystal with a density of 2.69 and a melting point of 587.5°C. White phosphorus (yellow phosphorus) dissolves in benzene, carbon disulfide, etc., and emits phosphorescence in moist air and is oxidized, becoming highly toxic (phosphorus poisoning). Black phosphorus is electrically conductive. White phosphorus (yellow phosphorus) is chemically highly active and spontaneously combusts in air, but the others are stable. It is widely distributed in nature as phosphate minerals such as apatite, and is an essential element for living organisms, forming part of DNA in the form of phosphoric acid derivatives, as well as being found in bones and teeth. In industry, yellow phosphorus is made by crushing and mixing phosphate rock, coke, and silica sand and heating them in an electric furnace, and collecting the resulting phosphorus vapor in water. Red phosphorus is made by heating yellow phosphorus to 200°C in an iron kettle, shielded from outside air. In addition to being used in matches and fireworks, phosphorus compounds have a wide range of uses, including fertilizers, detergents, pharmaceuticals, III-V compound semiconductors, and catalysts.
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Source : Heibonsha Encyclopedia About MyPedia Information

Japanese:

元素記号はP。原子番号15，原子量30.973761998。非金属元素の一つ。1669年ブラントが尿中より発見。白リン，紫リン，黒リンなど10種類以上の同素体があるが，完全には解明されていない。一般には，無定形または結晶質の赤リン，白リンの表面に赤リンの膜のできた黄リンが知られている。白リンは密度1.82，融点44.2℃，沸点280.5℃の無色の結晶。紫リンは比重2.35，融点589.5℃（43.1気圧），昇華点416℃の紫色結晶。黒リンは密度2.69，融点587.5℃の金属光沢のある鉄灰色結晶。白リン（黄リン）はベンゼン，二硫化炭素などに溶け，湿った空気中で燐光を発し酸化され，猛毒（リン中毒）。黒リンは電導性がある。また白リン（黄リン）は化学的に活性が強く空気中で自然に発火するが，他は安定。天然にはリン灰石などのリン酸塩鉱物として広く分布し，生体必須元素としてリン酸誘導体のかたちでDNAの一部を構成するほか，骨や歯などに含まれる。工業的にはリン鉱石，コークス，ケイ砂を粉砕混合し電気炉中で熱し，生じたリンの蒸気を水中に集めて黄リンとする。赤リンは黄リンを鉄製の釜中で外気を遮断(しゃだん)して200℃に熱してつくる。マッチや花火などに用いられるほか，リン化合物は肥料，洗剤，医薬品，III―V族化合物半導体，触媒など用途が広い。
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