Arsenic
Chemical, physical and material properties and data of the chemical element Arsenic.
General Information about Arsenic
Regular nameArsenicChemical symbolAsOther namesSystematic nameHistorical namesName meaning, originDiscovery (year)OccurencePosition in the PSEGroup membership
Atomar Properties of Arsenic
Atomic number Z33 = number of protonsStandard Atomic Weight74.921595 (6)
Electron configuration of Arsenic
| 1s | 2s | 2p | 3s | 3p | 3d | 4s | 4p | 4d | 4f | 5s | 5p | 5d | 5f | 6s | 6p | 6d | 6f | 7s | 7p |
|---|
| 2 | 2 | 6 | 2 | 6 | 10 | 2 | 3 | | | | | | | | | | | | |
Abbreviated form: [Ar] 3d10 4s2 4p3 .
Ionization Energies of Arsenic
The following table lists the ionization energies IE (ionization potentials); the IE is the energy required in electron volts (eV) per atom to separate a given electron from an Arsenic atom.
| IE1 | IE2 | IE3 | IE4 | IE5 | IE6 |
|---|
| 9.7886 | 18.5892 | 28.351 | 50.13 | 62.63 | 127.6 |
Isotopic Data of Arsenic
An overview of the nuclides as well as the isotopic data and properties are listed on the following page: Arsenic isotopes.
Chemistry of Arsenic
Oxidation states+ 3. + 5Electronegativity2.0 (Pauling original)
2.18 (Pauling)
2.211 (Allen)
2.2 (Mulliken)
2.53 (Sanderson)
2.20 (Allred-Rochow)
5.5372 eV (Gosh Gupta)
5.3 eV (Pearson)Electron affinity0.804 8(2) eV
77.65(2) kJ mol-1
Standard Electrode Potential
| E0 (V) | Symbol | Nox | Name Ox.
Name Red. | Ox.
Red. | e- |
|---|
| -0.23 | As | 0
- III | Arsenic
Arsane | As (s) + 3 H+
⇄ AsH3 (g) | + 3 e- |
| 0.24 | As | + III
0 | Arsenous acid
Arsenic | H3AsO3 (aq) + 3 H+
⇄ As (s) + 3 H2O | + 3 e- |
| 0.56 | As | + V
+ III | Arsenic acid
Arsenous acid | H3AsO4 (aq) + 2 H+
⇄ H3AsO3 (aq) + H2O | + 2 e- |
Material and Physical Properties
Melting point817 °CEnthalpy of fusion (molar)24.44 kJ mol-1Enthalpy of vaporization32.4 kJ mol-1Density5.727 g cm-3
External Data, Identifiers
CAS registry number7440-38-2InChI =1S/AsInChIKeyRQNWIZPPADIBDY-UHFFFAOYSA-NPubChem ID5359596
Last update: 2022-12-12
Perma link: https://www.chemlin.org/chemical-elements/arsenic.php
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