Arsenic (As)
metalloidSolid
Bobot Atom Standar
74,921595 uKonfigurasi elektron
[Ar] 4s2 3d10 4p3Titik lebur
816,85 °CTitik didih
613,85 °CMassa jenis
5776 kg/m³Bilangan oksidasi
−3, −2, −1, 0, +1, +2, +3, +4, +5Keelektronegatifan (Pauling)
2,18Energi ionisasi (ke-1)
9,78855 eVTahun penemuan
1250Jari-jari atom
115 pmDetail
Arsenic is a metalloid in group 15, chemically related to phosphorus and antimony. It occurs mainly in sulfide minerals and in arsenide or sulfosalt ores, rather than as the native element. Its chemistry is dominated by the +3 and +5 oxidation states, with important differences in mobility and toxicity among species. Arsenic is technologically useful in small quantities, especially in compound semiconductors, but it is better known for the toxicity of many of its inorganic compounds.
The element is a steel gray, very brittle, crystalline, semimetallic solid; it tarnishes in air, and when it is heated it rapidly oxidizes to arsenous oxide, which smells of garlic. Arsenic and its compounds are poisonous.
The name derives from the Latin arsenicium and the Greek arsenikos for "masculine" or "male" because the ancients thought that metals were different sexes. Arsenic was known in prehistoric times for its poisonous sulfides. The German scientist and philosopher, Albert von Bollstadt (Albert the Great or Albertus Magnus) is thought to have obtained the metal around 1250.
Although arsenic compounds were mined by the early Chinese, Greek and Egyptian civilizations, it is believed that arsenic itself was first identified by Albertus Magnus, a German alchemist, in 1250. Arsenic occurs free in nature, but is most often found in the minerals arsenopyrite (FeAsS), realgar (AsS) and orpiment (As2S3). Today, most commercial arsenic is obtained by heating arsenopyrite.
From the Latin word arsenicum, Greek arsenikon. Elemental arsenic occurs in two solid modifications: yellow, and gray or metallic, with specific gravities of 1.97, and 5.73, respectively. It is believed that Albertus Magnus obtained the element in 1250 A.D. In 1649 Schroeder published two methods of preparing the element. Mispickel arsenopyrite, (FeSAs), is the most common mineral from which, on heating, the arsenic sublimes leaving ferrous sulfide.
Pure arsenic is most commonly encountered as gray arsenic, a brittle, metallic-looking solid with a steel-gray surface. It sublimes readily on heating rather than melting at ordinary pressure. Yellow and black allotropes are known but are less stable under ordinary conditions.
Elemental arsenic has limited direct use. Small additions have been used to harden lead alloys, especially for shot, grids, and some bearing materials. The most important modern use is in high-purity compound semiconductors, notably gallium arsenide (GaAs), which is used in radio-frequency electronics, optoelectronics, infrared devices, and some high-efficiency solar cells. Arsenic compounds were formerly used widely in pesticides, herbicides, wood preservatives, pigments, and medicines, but many such uses have been restricted or abandoned because of toxicity and persistence.
Arsenic and its compounds are poisonous. They have been used to make rat poison and some insecticides. Small amounts of arsenic are added to germanium to make transistors. Gallium arsenide (GaAs) can produce laser light directly from electricity.
If you were paying careful attention to the physical data listed above, you may have noticed that arsenic's boiling point is lower than its melting point. This occurs because these two temperatures are measured at different atmospheric pressures. When heated at standard atmospheric pressure, arsenic changes directly from a solid to a gas, or sublimates, at a temperature of 887 K. In order to form liquid arsenic, the atmospheric pressure must be increased. At 28 times standard atmospheric pressure, arsenic melts at a temperature of 1090 K. If it were also measured at a pressure of 28 atmospheres, arsenic's boiling point would be higher than its melting point, as you would expect.
Arsenic is used in bronzing, pyrotechny, and for hardening and improving the sphericity of shot. The most important compounds are white arsenic, the sulfide, Paris green, calcium arsenate, and lead arsenate; the last three have been used as agricultural insecticides and poisons. Marsh's test makes use of the formation and ready decomposition of arsine. Arsenic is finding increasing uses as a doping agent in solid-state devices such as transistors. Gallium arsenide is used as a laser material to convert electricity directly into coherent light.
Isotopes in Biology
73As and 76As (with half-lives of 80.3 days and 1.1 days, respectively) are important radioactive tracers used in environmental and biomedical studies to quantify arsenic uptake [270] J. De Kimpe, R. Cornelis, L. Mees, R. Vanholder. Fundam. Appl. Toxicol.34, 240 (1996).. 74As (with a half-life of 17.8 days) has been used to investigate the biotransformation (modification of a chemical compound by an organism) of arsenate by mammals. In one study rabbits were injected with 74As-labeled arsenate. After a given amount of time, blood and blood products were sampled and tested for the presence and quantity of labeled arsenate metabolites [270] J. De Kimpe, R. Cornelis, L. Mees, R. Vanholder. Fundam. Appl. Toxicol.34, 240 (1996).. Inhalation of dust or smoke containing 74As is thought to be a causal agent of lung cancer. In one study [271] R. H. Holland, M. S. McCall, H. C. Lanz. Cancer Res.19, 1154 (1959)., the “absorption rate from the bronchial tree (a respiratory tract, which conducts air into the lungs) was rapid for the first several days and then tapered off slowly. In three patients an average of 45 percent of the inhaled arsenic was eliminated in the urine in 10 days and about 0.5 percent in the stools. The remainder must be assumed to have been deposited in the body, exhaled, and/or eliminated in body secretions and excreta over a long period of time.” See Fig. IUPAC.33.1.
Isotopes in Medicine
72As (with a half-life of 26 h) and 74As are useful in molecular imaging because they are radioactive isotopes that emit positrons that can be designed to bind to monoclonal antibodies (moAb), which accumulate in tumors and then 72As- or 74As-labeled ligands will bind to the moAbs. Once the 72As- or 74As-labeled ligand binds to the moAb, positron emission tomography (PET) is used to visualize the exact location of the tumor [272] M. Jennewein, A. Hermanne, R. P. Mason, P. E. Thorpe, F. Rösch. Nucl. Instrum. Methods Phys. Res. A569, 512 (2006).. A specific example of using radiolabeled antibodies for better imaging of tumors is the combination of 74As with bavituximab, which is an antibody that binds strongly to unique lipids on the surface of tumors. When a thiol group is introduced to bavituximab, arsenic is able to bind covalently, creating a simple and elegant radio-label for targeting cancerous tumors [269] M. Jennewein, M. A. Lewis, D. Zhao, E. Tsyganov, N. Slavine, J. He, L. Watkins, V. D. Kodibagkar, S. O’Kelly, P. Kulkarni, P. P. Antich, A. Hermanne, F. Rösch, R. P. Mason, P. E. Thorpe. Clin. Cancer Res.14, 1377 (2008)..
Arsenic forms covalent and ionic compounds in several oxidation states, chiefly −3, +3, and +5. Arsenic trioxide (As₂O₃) is a major industrial intermediate and dissolves to give arsenite species. Arsenic pentoxide (As₂O₅) and arsenic acid (H₃AsO₄) contain arsenic in the +5 state and are related to arsenate salts. Arsine (AsH₃) is a highly toxic, volatile hydride. Important minerals include arsenopyrite (FeAsS), realgar (As₄S₄), and orpiment (As₂S₃). Organoarsenic compounds also exist, including methylated species found in biological and environmental systems.
See more information at the Arsenic compound page.
Arsenic metal is hazardous mainly through dust, fumes, and conversion to soluble or volatile compounds. Many inorganic arsenic(III) compounds are acutely toxic, and chronic exposure to inorganic arsenic in drinking water or industrial settings is associated with serious disease, including cancers. Arsine (AsH₃) is especially dangerous because it is a potent hemolytic gas. Toxicity depends strongly on chemical form, dose, route of exposure, and solubility; organic arsenic species in seafood are often much less toxic than inorganic arsenic.
Arsenic enters the environment through natural weathering of minerals, volcanic emissions, geothermal waters, and human activities such as mining, smelting, coal combustion, and historical pesticide use. In groundwater, its mobility is controlled by pH, redox conditions, adsorption to iron and manganese oxides, and microbial transformations. Arsenate species generally predominate under oxidizing conditions, while arsenite species are more important under reducing conditions and are often more mobile and toxic.
Arsenic is not usually mined as a primary commodity. It is recovered mainly as arsenic trioxide (As₂O₃) from flue dusts and residues generated during the smelting and refining of copper, lead, gold, and other nonferrous ores. Demand is much smaller than in the past because agricultural chemicals and chromated copper arsenate wood preservatives have been reduced or phased out in many regions. High-purity arsenic for gallium arsenide (GaAs) is a specialized market requiring stringent purification. Supply depends heavily on by-product recovery, environmental controls at smelters, and the ability to handle or stabilize arsenic-bearing wastes.
Found in mispickel (arsenopyrite)
Arsenic is a relatively uncommon element in the cosmos. Its stable isotope, ⁷⁵As, is produced by neutron-capture processes in evolved stars and supernova-related environments. In planetary materials, arsenic behaves as a moderately chalcophile and siderophile trace element, so it is commonly associated with sulfides and metallic phases rather than silicate minerals alone. Meteorites contain small amounts of arsenic in mineral and metal fractions.
- Natural arsenic consists essentially of one stable isotope, ⁷⁵As.
- Gray arsenic sublimes at ordinary pressure, which complicates simple melting-point measurements.
- Garlic-like odor during heating often comes from volatile arsenic compounds, not a safe warning sign.
- Arsenopyrite (FeAsS) is one of the most important arsenic-bearing ore minerals.
- Gallium arsenide (GaAs) has higher electron mobility than silicon, but it is costlier and more brittle.
- Some microorganisms can transform arsenic between arsenite, arsenate, and methylated forms.
Gambar
Sifat
Fisika
- Jari-jari atom (empiris)
- 115 pm Bandingkan Jari-jari atom (empiris) semua unsur →
- Jari-jari kovalen
- 119 pm Bandingkan Jari-jari kovalen semua unsur →
- Jari-jari van der Waals
- 185 pm Bandingkan Jari-jari van der Waals semua unsur →
- Jari-jari logam
- 121 pm Bandingkan Jari-jari logam semua unsur →
- Massa jenis
- 5776 kg/m³ Bandingkan Massa jenis semua unsur →
- Volume molar
- 0,0131 L/mol
- Fase pada STP
- Padat Bandingkan Fase pada STP semua unsur →
- Titik lebur
- 816,85 °C Bandingkan Titik lebur semua unsur →
- Titik didih
- 613,85 °C Bandingkan Titik didih semua unsur →
- Kapasitas kalor spesifik
- 0,329 J/(g·K) Bandingkan Kapasitas kalor spesifik semua unsur →
- Kapasitas kalor molar
- 24,64 J/(mol·K) Bandingkan Kapasitas kalor molar semua unsur →
- Struktur kristal
- Rombohedral Bandingkan Struktur kristal semua unsur →
Kimia
- Keelektronegatifan (Pauling)
- 2,18 Bandingkan Keelektronegatifan (Pauling) semua unsur →
- Keelektronegatifan (Allen)
- 2,211
- Afinitas elektron
- 0,81 eV
- Energi ionisasi (ke-1)
- 9,78855 eV Bandingkan Energi ionisasi (ke-1) semua unsur →
- Energi ionisasi (ke-2)
- 18,589264 eV Bandingkan Energi ionisasi (ke-2) semua unsur →
- Energi ionisasi (ke-3)
- 28,349098 eV Bandingkan Energi ionisasi (ke-3) semua unsur →
- Energi ionisasi (ke-4)
- 50,150173 eV Bandingkan Energi ionisasi (ke-4) semua unsur →
- Energi ionisasi (ke-5)
- 62,770216 eV Bandingkan Energi ionisasi (ke-5) semua unsur →
- Bilangan oksidasi
- −3, −2, −1, 0, +1, +2, +3, +4, +5 Bandingkan Bilangan oksidasi semua unsur →
- Elektron valensi
- 5 Bandingkan Elektron valensi semua unsur →
- Alotrop
- ["gray"]
- Konfigurasi elektron
- [Ar] 4s2 3d10 4p3
Termodinamika
- Titik tripel (suhu)
- 817 °C
- Titik tripel (tekanan)
- 3,7e+6 Pa
- Titik kritis (suhu)
- 1400 °C
- Titik kritis (tekanan)
- 2,23e+7 Pa
- Kalor penguapan
- 0,36275069 eV Bandingkan Kalor penguapan semua unsur →
- Kalor sublimasi
- 3,138312 eV
- Kalor atomisasi
- 3,138312 eV
- Entalpi atomisasi
- 3,135202 eV
Nuklir
- Proton
- 33 Bandingkan Proton semua unsur →
- Neutron
- 42 Bandingkan Neutron semua unsur →
- Isotop yang diketahui
- 33 Bandingkan Isotop yang diketahui semua unsur →
- Isotop stabil
- 1 Bandingkan Isotop stabil semua unsur →
- Isotop paling stabil
- As-75
- Tahun penemuan
- 1250
Kelimpahan
- Kelimpahan (kerak Bumi)
- 1,8 mg/kg Bandingkan Kelimpahan (kerak Bumi) semua unsur →
- Kelimpahan (samudra)
- 3,7 mg/L Bandingkan Kelimpahan (samudra) semua unsur →
Struktur Kristal
- Konstanta kisi a
- 413 pm
Struktur Elektronik
- Elektron per kulit
- 2, 8, 18, 5 Bandingkan Elektron per kulit semua unsur →
Pengenal
- Nomor CAS
- 7440-38-2 Bandingkan Nomor CAS semua unsur →
- Simbol term
- 4S°3/2
- InChI
- InChI=1S/As
- Kunci InChI
- RQNWIZPPADIBDY-UHFFFAOYSA-N
Konfigurasi Elektron Diukur
As: 3d¹⁰ 4s² 4p³[Ar] 3d¹⁰ 4s² 4p³1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p³Model atom
Isotop mengubah jumlah neutron, massa, dan kestabilan — bukan konfigurasi elektron atom netral.
Model atom skematis, tidak sesuai skala.
Sidik Jari Atom
Spektrum Emisi / Absorpsi
Distribusi Isotop
| Nomor massa | Massa atom (u) | Kelimpahan alami | Waktu paruh |
|---|---|---|---|
| 75 Stabil | 74,92159457 ± 0,00000095 | 100,0000% | Stabil |
Fase / Wujud
Alasan: 588,9 °C di bawah titik sublimasi (613,85 °C)
Skematis, tidak sesuai skala
Titik transisi fase
Energi transisi
Energi yang diperlukan untuk menguapkan 1 mol pada titik didih
Energi yang diperlukan untuk menyublimkan 1 mol pada titik sublimasi
Massa jenis
Pada kondisi standar
Pada kondisi standar
Lanjutan
Spektrum Atom
Menampilkan 10 dari 33. Diurutkan berdasarkan muatan ion (menaik).
Data Garis Spektrum ?
| Ion | Muatan | Total garis | Probabilitas transisi | Penamaan tingkat energi |
|---|---|---|---|---|
| As I | 0 | 52 | 14 | 51 |
| As II | +1 | 86 | 0 | 0 |
| As III | +2 | 14 | 0 | 0 |
| As IV | +3 | 8 | 0 | 0 |
| As V | +4 | 9 | 0 | 0 |
Data Tingkat Energi ?
| Ion | Muatan | Tingkat energi |
|---|---|---|
| As I | 0 | 116 |
| As II | +1 | 167 |
| As III | +2 | 22 |
| As IV | +3 | 34 |
| As V | +4 | 9 |
| As VI | +5 | 44 |
| As VII | +6 | 50 |
| As VIII | +7 | 2 |
| As IX | +8 | 2 |
| As X | +9 | 2 |
Jari-jari Ion
| Muatan | Koordinasi | Spin | Jari-jari |
|---|---|---|---|
| +3 | 6 | Tidak tersedia | 57.99999999999999 pm |
| +5 | 4 | Tidak tersedia | 33.5 pm |
| +5 | 6 | Tidak tersedia | 46 pm |
Senyawa
Isotop (1)
| Nomor massa | Massa atom (u) | Kelimpahan alami | Waktu paruh | Mode peluruhan | |
|---|---|---|---|---|---|
| 75 Stabil | 74,92159457 ± 0,00000095 | 100,0000% | Stabil | stable |
Sifat Lanjutan
Jari-jari Kovalen (Lanjutan)
- Jari-jari kovalen (Pyykkö)
- 121 pm
- Jari-jari kovalen (Pyykkö, ikatan rangkap dua)
- 114 pm
- Jari-jari kovalen (Pyykkö, ikatan rangkap tiga)
- 106 pm
- Jari-jari kovalen (Bragg)
- 126 pm
Jari-jari van der Waals
- Bondi
- 185 pm
- Batsanov
- 205 pm
- Alvarez
- 188 pm
- UFF
- 423 pm
- MM3
- 236 pm
- Dreiding
- 415 pm
Jari-jari Atom & Logam
- Jari-jari atom (Rahm)
- 231 pm
- Jari-jari logam (C12)
- 148 pm
Skala Penomoran
- Mendeleev
- 95
- Pettifor
- 89
- Glawe
- 90
Skala Keelektronegatifan
- Ghosh
- 0
- Miedema
- 5
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizabilitas & Dispersi
- Polarizabilitas dipol
- 30 a.u.
- Polarizabilitas dipol (ketidakpastian)
- 1 a.u.
- C₆
- 246 Ha·Bohr6
- C₆ (Gould–Bučko)
- 260 Ha·Bohr6
Parameter Miedema
- Volume molar Miedema
- 11,85 cm3/mol
- Kerapatan elektron Miedema
- 3
Risiko Pasokan & Ekonomi
- Konsentrasi produksi
- 64
- Risiko pasokan relatif
- 8
- Stabilitas politik (produsen terbesar)
- 24
Transisi Fase & Alotrop
| Titik lebur | 1090,15 K |
| Titik didih | 889,15 K |
| Titik kritis (suhu) | 1673,15 K |
| Titik kritis (tekanan) | 22,3 MPa |
| Titik tripel (suhu) | 1090,15 K |
| Titik tripel (tekanan) | 3700 kPa |
Kategori Bilangan Oksidasi
Data Referensi Lanjutan
Konstanta Pemerisaian (8)
| n | Orbital | σ |
|---|---|---|
| 1 | s | 0,7217 |
| 2 | p | 3,9264 |
| 2 | s | 8,873 |
| 3 | d | 15,6216 |
| 3 | p | 15,1503 |
| 3 | s | 14,4045 |
| 4 | p | 25,5508 |
| 4 | s | 24,056 |
Detail Jari-jari Kristal (3)
| Muatan | CN | Spin | rcrystal (pm) | Asal |
|---|---|---|---|---|
| 3 | VI | 72 | Ahrens (1952) ionic radius, | |
| 5 | IV | 47,5 | from r^3 vs V plots, | |
| 5 | VI | 60 | calculated, |
Mode Peluruhan Isotop (50)
| Isotop | Mode | Intensitas |
|---|---|---|
| 60 | p | — |
| 61 | p | — |
| 62 | p | — |
| 63 | p | — |
| 64 | B+ | 100% |
| 64 | B+p | — |
| 65 | B+ | 100% |
| 65 | B+p | — |
| 66 | B+ | 100% |
| 67 | B+ | 100% |
Faktor Hamburan Sinar-X (506)
| Energi (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 4,62596 |
| 10,1617 | — | 4,67742 |
| 10,3261 | — | 4,72945 |
| 10,4931 | — | 4,78206 |
| 10,6628 | — | 4,83525 |
| 10,8353 | — | 4,88904 |
| 11,0106 | — | 4,94342 |
| 11,1886 | — | 4,99841 |
| 11,3696 | — | 5,05401 |
| 11,5535 | — | 5,11023 |
Data Tambahan
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
1.8 milligrams per kilogram
Referensi (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
3.7-3 milligrams per liter
Referensi (1)
Referensi
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
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The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Arsenic.
The element property data was retrieved from publications.