Electronic data		Thermal data		Steric data
Shells: 2,8,18,5 Orbitals: [Ar] 3d10 4s2 4p3 Electronegativity: 2.2, 2.0 1. Ionization potential: 9.8152 eV 2. Ionization potential: 18.633 eV 3. Ionization potential: 28.351 eV Oxidation states: 5,3,-3 Electrical conductivity: 0.0345 10^6		Melting point: 817 °C @ 28 atmos. Boiling point: 613 °C Sublimes at Specific heat: 0.33 J/gK Heat of fusion: -- kJ/mol Heat of vaporization: 34.760 kJ/mol Thermal conductivity: 0.500 W/cmK		Atomic radius: 1.33 Å Ionic radius: 0.58 Å () Covalent radius: 1.20 Å Atomic volume: 13.1 cm³/mol Density (293 K): 5.72 g/cm³ Crystal structure: Rhombohedral

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
71As	0	71	5/2	2.72d	EC,+	View
72As	0	72	2	26.0h	+,EC	View
73As	0	73	3/2	80.3d	EC	View
74As	0	73.924	2	17.78d	EC,+,-	View
75As	100	74.9216	3/2	--	stable	--
76As	0	75.922	2	26.3h	-	View
77As	0	76.921	3/2	38.8h	-	View

Legend

Name origin:	Greek: arsenikon; Latin: arsenicum, (both names for yellow pigment)
Description:	Steel-gray, brittle semi-metal.
Discovered by:	Known to the ancients
Year:	--
Place:	Unknown
Sources:	Found in mispickel (arsenopyrite).
Use(s):	Many of its compounds are deadly poison and used as weed killer and rat poison. Conducts electricity. Used in semiconductors. Some compounds, called arsenides, are used in the manufacture of paints, wallpapers, and ceramics.