Phosphorus
by: Marianne Bird
Phosphorus is a chemical element found on the periodic table in group 3. It has the atomic number 15 and symbol P. The atomic mass of Phosphorus is 30.9; containing 15 electrons and 16 neutrons. It's melting point is 111.38° F. Phosphorus can be colorless, white, yellow, red, violet or black. It is very reactive and is not found as a free element, in mineral form it is phosphate. The discovery of Phosphorus is credited to German chemist, Hennig Brand in 1669. Brand discovered phosphorus by using heat to evaporate human urine, which produced a white substance that emitted a glowing light.
Phosphorus exists in different allotropes, but the two elemental forms are white phosphorus and red phosphorus. White phosphorus emits a glow when exposed to oxygen; and is where the word phosphorescence originates. However, it is actually a cold chemical reaction, chemiluminescence, which gives Phosphorus its glow, not phosphorescence. White phosphorus is the least dense and most unstable, toxic and volatile form of Phosphorus. White phosphorus is extremely flammable, and pyrophoric when exposed to air at 86°F; the odor emitted when burning is similar to garlic. White Phosphorus is not soluble in water but is in carbon disulfide. White phosphorus slowly transforms into red phosphorus with heat and sunlight. Red phosphorus is not considered an allotrope but an intermediate phase between white and violet phosphorus. It is more stable than white phosphorus and will only combust at 572° F however red phosphorus is still considered to be highly reactive.
Phosphorus is found in bone structure and teeth as well as in urine and guano. It is also found in the earth's crust at 1 gram per kilogram, and has been detected in Cassiopeia A by astronomers, confirming that phosphorus is a by-product of supernova nucleosynthesis. Phosphorus is essential to all living things and is a key nutrient to plants. Because it has a very slow natural cycle and natural carriers of phosphorus are mostly insoluble and inaccessible to plants, it is produced as phosphate for use in agricultural fertilizers. Phosphorus is also integral to the production of steel, matches and water softening. Phosphates are also used in soft drinks, meats, cheeses, tooth paste and baking powder.
Widely used compounds | Use |
---|
Ca(H2PO4)2·H2O |
Baking powder and fertilisers |
CaHPO4·2H2O |
Animal food additive, toothpowder |
H3PO4 |
Manufacture of phosphate fertilisers |
PCl3 |
Manufacture of POCl3 and pesticides |
POCl3 |
Manufacture of plasticiser |
P4S10 |
Manufacturing of additives and pesticides |
Na5P3O10 |
Detergents
|
White Phosphorus glowing after being exposed to air.
Works cited:
https://en.wikipedia.org/wiki/Phosphorus
https://www.strongnet.org/cms/lib6/OH01000884/Centricity/ModuleInstance/2567/Chapter_11_Notes.pdf
http://www.chemicalelements.com/elements/p.html
Comments (1)
Mitch Albers said
at 7:46 pm on Jan 16, 2020
Nice post!
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