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Arsenic
Electrons per shell 2,8,18,5
Electron Configuration [Ar] 3d10 4s2 4p3 open electron config
Ground state 43/2
Atomic Volume 13.1 cm3 mol-1
Electronegativity 2.18
Magnetic ordering No data
Mass magnetic susceptibility -3.9 x 10-9
Molar magnetic susceptibility -2.92 x 10-10
Thermal Properties
Enthalpy of Atomization 301.3 kJ mol-1 @25°C
Enthalpy of Fusion 27.7 kJ mol-1
Enthalpy of Vaporisation 31.9 kJ mol-1
Heat Capacity 24.64 J mol-1 K-1
Thermal Conductivity 50.2 W m-1 K-1
Thermal Expansion No data.
Hardness
Brinell hardness 1440 MPa
Mohs hardness 3.5
Elastic Properties
Bulk modulus 22 GPa
Young's modulus 8 GPa
Electrical Properties
Electrical resistivity 3.0 x 10-7 Ω m
Electrical conductivity 0.0345 106/cm Ω
Chemical Properties
Electrochemical Equivalent 0.93177 g Ah-1
Electron Work Function 3.75 eV
Valence Electron Potential (-eV) 74
Ionization Potential  
First 9.81
Second 16.633
Third 28.351
Incompatibilities Halogenated compounds, rubidium, carbide.
Optical Properties
Refractive Index (solid) 1.001552
Energy Levels
Kα1 (intensity 100) 10.54372 KeV
Kα2 (intensity 50) 10.50799 KeV
Kβ1 (intensity 14.7) 11.7262 KeV
Kβ3 (intensity 7.4) 11.7184 KeV
Lα1 (intensity 100) 1.282 KeV
Lα2 (intensity 10) 1.282 KeV
Lβ1 (intensity 32.8) 1.317 KeV
Lβ3 (intensity 0.2) 1.3835 KeV
Lβ4 (intensity 3) 1.388 KeV
Lγ3 (intensity 3) 1.155 KeV
Ll (intensity 6) 1.1207 KeV
Atomic Radii
Empirical 115 pm
Bohr Radius 114 pm
Covalent Radius 119 pm
Van der Waals 185 pm
Triple covalent 106 pm
Metallic No data.
Oxidation States
Main As+3, As+5
Other As-3
Ionisation Energies (kJ mol-1) show graph
M - M+ 947
M+ - M2+ 1798
M2+ - M3+ 2735
M3+ - M4+ 4837
M4+ - M5+ 6042
M5+ - M6+ 12305
M6+ - M7+ 15400
M7+ - M8+ 18900
M8+ - M9+ 22600
M9+ - M10+ 26400
Covalent Bonds (kJ mol-1)
As-H 245
As-C 200
As-O 477
As-F 464
As-Cl 293
As-As 348
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 553 596 646 706 781 874
Crystal Structure
Structure Trigonal
a = 375.98 pm
b = 375.98 pm
c = 1054.75 pm
α = 90°
β = 90°
γ = 120°