Relative atomic mass: 74.92160 +- 0.00002

English: Arsenic
French: Arsenic
Croatian: Arsen
German: Arsen
Italian: Arsenico
Spanish: Arsenico

Atomic number: 33
Group numbers: 15
Period: 4
Standard state (20 oC): solid

Discovery: 1250 Albertus Magnus (DE)
Arsenic was discovered by Albertus Magnus (DE) in 1250. The origin of the name comes from the Greek word arsenikon meaning yellow orpiment. It is a steel-grey, brittle semi-metal that resists water, acids and alkalis. It tarnishes in air, burns in oxygen and is highly toxic by inhalation or ingestion. Arsenic is found in mispickel (arsenopyrite). Many of its compounds are deadly poison and used as weed killer and rat poison. Some compounds, called arsenides, are used in the manufacture of paints, wallpapers and ceramics. It is also used in semiconductors The price of 99.5 % pure arsenic sponge is 322.60 for 100 g.
Electronic configuration: [Ar] 3d10 4s2 4p3
Formal oxidation number: -3 +3 +5
Atomic radius: 124.5 pm

Electronegativities: 2.18
Thermal conductivity: 50 W/(m K)
Electrical resistivity (20 oC): 33.3 microOhm cm

Melting point: 817 oC
Boiling point: 614 oC

Heat of fusion: 27.7 kJ/mol
Heat of vaporization: 31.9 kJ/mol
Heat of atomization: 301.42 kJ/mol

32Ge <= 33As => 34Se

ASCII Periodic Table of the Elements
29 Aug. 2017
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