|
|
| Arsenic | |
| Electron Configuration | 2,8,18,5 |
| Electron Configuration | [Ar] 3d10 4s2 4p3 |
| Ground state | 4S°3/2 |
| Atomic Volume | 13.1 g/cm3 |
| 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 | No data. |
| 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. |
| Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 3 | VI | 0.72 | 0.58 | A |
| 5 | IV | 0.475 | 0.335 | R* |
| VI | 0.6 | 0.46 | C* | |
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
| Oxidation States |
|
| Main
|
As+3, As+5 |
| Other
|
As-3 |
Ionisation Energies (kJ mol-1)  |
|
| 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° | |