Cassandramjb's List: Arsenic Report

• Atomic Number: 33

  Atomic Weight: 74.92160

  Melting Point: 1090 K (817°C or 1503°F)

  Boiling Point: 887 K (614°C or 1137°F)

  Density: 5.776 grams per cubic centimeter

  Phase at Room Temperature: Solid

  Element Classification: Semi-metal

  Period Number: 4    Group Number: 15    Group Name: Pnictogen
• mined by the early Chinese, Greek and Egyptian civilizations
• first identified by Albertus Magnus, a German alchemist, in 1250
• often found in the minerals arsenopyrite (FeAsS), realgar (AsS) and orpiment (As₂S₃)
• occurs free in nature
• commercial arsenic is obtained by heating arsenopyrite
• poisonous
• rat poison and some insecticides
• . Gallium arsenide (GaAs) can produce laser light directly from electricity.
• arsenic's boiling point is lower than its melting point
• • Read the explanation here.

• Estimated Crustal Abundance: 1.8 milligrams per kilogram

  Estimated Oceanic Abundance: 3.7-3 milligrams per liter

10 more annotations...

• 1st century A.D., Pliny stated that sandarach is found in gold and silver mines and arsenic (arsenic trioxide) is composed of the same matter as sandarach
• Aristotle makes reference to sandarach (arsenic trisulfide) in the 4th century B.C
• white, yellow and red - since then recognized as arsenic trioxide, arsenic trisulfide (orpiment) and arsenic disulfide
• N. Lemery also observed that metallic arsenic was produced by heating arsenic trioxide with soap and potash.
• 1649 that J. Schroder clearly reported the preparation of metallic arsenic by reducing arsenic trioxide with charcoal
• sufficiently known to classify it as semimetal

4 more annotations...

• Arsenic has been known since antiquity in its sulfide compound.
• Aristotle, in the fourth century BC, refers to “sandarach” renamed arhenicum by his student Theophrastus of Eresos.
• Olympiodorus of Thebes (5th century AD) roasted arsenic sulfide and obtained white arsenic (As₂O₃).
• Albertus Magnus (1193-1280), a German philosopher and theologian, was the first to state that arsenic has a metal-like nature. In De Mineralibus he described how the metal could be obtained by heating orpiment (As₂S₃) with soap.
• Two methods of preparing arsenic were published by German pharmacist Johann Schroeder in 1649.
• Greek word ‘arsenikos’ meaning potent
• Arsenic is immediately dangerous to life or health at 5 mg m^-3
• pure arsenic is much less dangerous than As^(III) compounds such as AsH₃ and As₂O₃ which are absorbed easily and are carcinogenic with high toxicity.
• Gray arsenic is the most common
• Yellow arsenic is metastable
• Black arsenic can be prepared by cooling arsenic vapor at 100 ^oC – 200 ^oC
• arsenic compounds are used in wood preservation and insecticides
• Gallium arsenide (GaAs) is a semiconductor used in laser diodes and LEDs.
• Small amounts of arsenic (less than two percent) can be used in lead alloys for ammunition
• arsenic is also an essential element, necessary to our physiology. A level of 0.00001% is needed for growth and for a healthy nervous system.

• Abundance earth’s crust: 1.8 parts per million by weight, 0.5 parts per million by moles

   

  Abundance solar system: 12 parts per billion by weight, 0.21 parts per billion by moles
• Most arsenic is obtained as a by-product of processing gold, silver, copper, and other metal ores.

15 more annotations...

• primary ore of arsenic metal
• iron arsenic sulfide, FeAsS

• before penicillin was developed an arsenic compound was used to treat syphilis and yaws.
• is used in ammunition manufacturing because it helps to create harder and rounder bullets.
• is used in small quantities in semi-conductor manufacturing
• is used as a preservative in tanning and taxidermy, as well as on the exterior of wood such as deck and playground materials.

2 more annotations...