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About Arsenic

Arsenic Bohr

The discovery of arsenic is generally attributed to Saint Albertus Magnus, sometimes known as Albert the Great, as there are records of the bishop, scholar, and alchemist producing elemental arsenic in 1250 AD. However, arsenic compounds have been known since antiquity, and earlier alchemists may have accomplished this feat as well. Whereas many more recently discovered elements have names with Greek roots, arsenic’s roots are older, as the Greek arsenikon was derived from Syriac and Persian words for “yellow orpiment”, which is a naturally occurring arsenic sulfide mineral. The name came into Latin as arsenicum, and to old French as arsenic, which was adopted as the English word for the element.

Arsenic’s cultural history is curiously paradoxical, as it has been used as both medicine and poison for centuries. Hippocrates prescribed orpiment for ulcers, and ancient Chinese medicine used arsenic compounds to treat a variety of ailments. In the 18th century, Thomas Fowler made popular the patent medicine “Fowler’s solution”, a liquid formulation of potassium arsenite that was sold as a remedy for complaints as diverse as asthma, eczema, and malaria. At the same time, arsenic compounds were well known as poisons that they were used to kill pests and people in medieval Europe. The French knew arsenic trioxide, an odorless compound that easily mixed into food or drink, as “poudre de succession”--”Inheritance powder”, because it was used so commonly used in homicides.

Intentional arsenic poisonings became less common after a reliable method for detecting arsenic in a diseased person, the Marsh test, was introduced in 1836, but many modern uses of the element continued to take advantage of its toxicity. A variety of arsenic compounds have been used as pesticides and herbicides and in wood preservatives, though the toxicity of such products to the humans working with them has led to their replacement by safer alternatives for some applications. The deadly properties of arsenic have even been weaponized--a number of chemical agents used in the first world war were arsenic compounds, and Agent Blue, one of the “rainbow herbicides” used in the Vietnam war, was a potent arsenic herbicide.

Arsenic-based medical treatments also have modern counterparts. An arsenic containing drug called Salvarsan was developed as a syphilis treatment in the early 20th century, and remained in use until penicillin became available in the 1940s. The arsenic containing drug Melarsoprol is still sometimes used as a treatment for late stages of African trypanosomiasis--known colloquially as African sleeping sickness--despite significant side effects related to arsenic toxicity. Arsenic is also used in the treatment of several cancers, particularly in recurrences of acute promyelocytic leukemia following first line treatments.

A third historical use for arsenic was in metal alloys. Early bronze was made from arsenic and copper; it was only later that tin replaced arsenic. Brass even today sometimes contain arsenic, which lessens corrosive loss of zinc from the copper-zinc alloy. The primary modern use of arsenic in alloys, however, is in lead alloys. The addition of arsenic makes lead, a soft metal, significantly harder, and such alloys are used in standard lead-acid car batteries.

Other modern uses of arsenic have no historical precedent; a prime example is arsenic’s use in semiconductors. Arsenic is a component of many III-V type semiconductors as well as semiconducting compounds with more complex formulations. The most common III-V semiconductor is gallium arsenide. Gallium arsenide was developed in the 1960s as a semiconductor with somewhat different electrical properties than the more common silicon, and that is more suited than silicon to some applications. Notably, gallium arsenide is a direct band gap semiconductor, which means that it can both absorb and emit light with high efficiency. This lends it to use in LEDs and lasers. Additionally, extremely thin layers of gallium arsenide can be used to effectively absorb all the photons from incident sunlight, as opposed to the thick layers of silicon required for the same task. This allows for the creation of one type of thin-film photovoltaic cell. GaAs-based semiconductor devices also exhibit less noise than those produced from silicon, and are thus favored in many telecommunications applications. The other III-V arsenic semiconductors have similar uses to gallium arsenide, and semiconductors with more complex formulations are generally used in settings where the ability to tune the material’s band gap through adjustments to the precise molecular composition are desirable.

In nature, arsenic is most commonly found in minerals in combination with sulfur and sometimes iron, nickel, or copper. The two forms of arsenic sulfide, realgar and orpiment, were often used as sources of arsenic in antiquity. The most common form of arsenic used in industry is arsenic trioxide, which may be produced by roasting any of these minerals in air. Roasting the same minerals without oxygen present will produce metallic arsenic. Arsenic is rarely harvested directly, but rather produced as a side product of the mining and purification of other metal ores.

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Elemental Arsenic Picture

Summary. Arsenic has numerous applications as a semiconductor and other electronic applications as Indium arsenide, silicon arsenide and tin arsenide. Arsenic is finding increasing uses as a doping agent in solid-state devices such as transistors. Gallium arsenideHigh Purity (99.99999%) Arsenic (As) Sputtering Target is a semiconductor material frequently used in optoelectronic applications. Arsenic is used in bronzing and for hardening and improving the sphericity of shot. Due to their toxicity, arsenic compounds are used in insecticides and wood preservation. High Purity (99.9999%) Arsenic Oxide (As2O3) PowderArsenic is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Arsenic oxides are insoluble arsenic compounds available in powder and dense pellet form for such uses as optical coating and thin film applications. Arsenic is also available in soluble forms including chlorides, and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Arsenic Properties

Arsenic (As) atomic and molecular weight, atomic number and elemental symbolArsenic is a Block P, Group 15, Period 4 element.Elemental Arsenic Arsenic Bohr ModelThe number of electrons in each of Arsenic's shells is 2, 8, 18, 5 and its electron configuration is [Ar] 3d10 4s2 4p3.The arsenic atom has a radius of and its Van der Waals radius is In its elemental form, CAS 1327-53-3, arsenic has a metallic grey appearance. Arsenic is found in numerous minerals including arsenolite (As2O3), arsenopyrite (FeAsS), loellingite (FeAs2), orpiment (As2S3), and realgar (As4S4). Arsenic was discovered in the early Bronze Age, circa 2500 BC. It was first isolated by Albertus Magnus in 1250.

Symbol: As
Atomic Number: 33
Atomic Weight: 74.92
Element Category: metalloid
Group, Period, Block: 15 (pnictogens), 4, p
Color: metallic gray/ gray
Other Names: Arsen, Arsenico, Arsenik
Melting Point: 616 °C, 1140.8 °F, 889.15 K
Boiling Point: Sublimes
Density: 5.778 kg·m3
Liquid Density @ Melting Point: 5.22 g/cm3
Density @ 20°C: 5.776 g/cm3
Density of Solid: 5727 kg·m3
Specific Heat: 0.328 kJ/kg/K
Superconductivity Temperature: N/A
Triple Point: 1090 K, 3628 kPa
Critical Point: 1673 K,  MPa
Heat of Fusion (kJ·mol-1): 27.7
Heat of Vaporization (kJ·mol-1): 31.9
Heat of Atomization (kJ·mol-1): 301.42
Thermal Conductivity: W/cm/ K @ 298.2 K
Thermal Expansion: N/A
Electrical Resistivity: 260 nΩ·m at 0°C
Tensile Strength: N/A
Molar Heat Capacity: 24.64 J·mol-1·K-1
Young's Modulus: 8 GPa
Shear Modulus: N/A
Bulk Modulus: 22 GPa
Poisson Ratio: N/A
Mohs Hardness: 3.5
Vickers Hardness: N/A
Brinell Hardness: 1440 MPa
Speed of Sound: N/A
Pauling Electronegativity: 2.18
Sanderson Electronegativity: 2.82
Allred Rochow Electronegativity: 2.2
Mulliken-Jaffe Electronegativity: 2.26 (20% s orbital)
Allen Electronegativity: 2.211
Pauling Electropositivity: 1.82
Reflectivity (%): N/A
Refractive Index: 1.001552 
Electrons: 33
Protons: 33
Neutrons: 42
Electron Configuration: [Ar] 3d10 4s2 4p3
Atomic Radius: 119 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 119±4 pm
Covalent Radius (Å): 1.2
Van der Waals Radius: 185 pm
Oxidation States: 5, 3, -3
Phase: Solid
Crystal Structure: simple trigonal
Magnetic Ordering: diamagnetic
Electron Affinity (kJ·mol-1) 77.574
1st Ionization Energy: 944.46 kJ·mol-1
2nd Ionization Energy: 1797.82 kJ·mol-1
3rd Ionization Energy: 2735.48 kJ·mol-1
CAS Number: 7440-38-2
EC Number: 231-148-6
MDL Number: MFCD00085309
Beilstein Number: N/A
SMILES Identifier: [AsH3]
InChI Identifier: InChI=1S/As
PubChem CID: 5359596
ChemSpider ID: 4514330
Earth - Total:  3.2 ppm 
Mercury - Total: 6.4 ppm
Venus - Total: 3.1 ppm
Earth - Seawater (Oceans), ppb by weight: 2.3
Earth - Seawater (Oceans), ppb by atoms: 0.19
Earth -  Crust (Crustal Rocks), ppb by weight: 2100
Earth -  Crust (Crustal Rocks), ppb by atoms: 580
Sun - Total, ppb by weight: N/A
Sun - Total, ppb by atoms: N/A
Stream, ppb by weight: 1
Stream, ppb by atoms: 0.01
Meterorite (Carbonaceous), ppb by weight: 1800
Meterorite (Carbonaceous), ppb by atoms: 460
Typical Human Body, ppb by weight: 50
Typical Human Body, ppb by atom: 4
Universe, ppb by weight: 8
Universe, ppb by atom: 0.1
Discovered By: Ancients
Discovery Date: Bronze Age circa 2500 BC
First Isolation: Albertus Magnus (1250)

Health, Safety & Transportation Information for Arsenic

Though inorganic Arsenic is extremely toxic, even in very small amounts, other forms of arsenic have proven safe and even potentially beneficial to humans. Safety data for Arsenic and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Arsenic.

Safety Data
Signal Word Danger
Hazard Statements H301-H331-H410
Hazard Codes T, N
Risk Codes 23/25-50/53
Safety Precautions 20/21-28-45-60-61
RTECS Number CG0525000
Transport Information UN 1558 6.1/PG 2
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Skull and Crossbones-Acute Toxicity  Environment-Hazardous to the aquatic environment
Review and Print SDS Arsenic Metal


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Arsenic Metal

Product Number: All applicable American Elements product codes, e.g. AS-E-03, AS-E-04, AS-E-05, AS-E-06, AS-E-07

CAS #: 7440-38-2

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
GHS06 Skull and crossbones
Acute Tox. 3 H301 Toxic if swallowed.
Acute Tox. 3 H331 Toxic if inhaled.
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
The substance is classified and labeled according to the CLP regulation.
Hazard pictograms

Skull and Crossbones - GHS06

Signal word
Hazard statements
H301+H331 Toxic if swallowed or if inhaled.
Precautionary statements
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
P304+P340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing.
P321 Specific treatment (see on this label).
P405 Store locked up.
P403+P233 Store in a well-ventilated place. Keep container tightly closed.
P501 Dispose of contents/container in accordance with local/regional/
national/international regulations.
WHMIS classification
D1A - Very toxic material causing immediate and serious toxic effects
D2A - Very toxic material causing other toxic effects
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)
Health (acute effects) = 3
Flammability = 1
Physical Hazard = 1
Other hazards
Results of PBT and vPvB assessment
Not applicable.
Not applicable.


Chemical characterization: Substances
CAS# Description:
7440-38-2 Arsenic
Identification number(s):
EC number:
Index number:


Description of first aid measures
General information
Immediately remove any clothing soiled by the product.
Remove breathing apparatus only after contaminated clothing has been completely removed.
In case of irregular breathing or respiratory arrest provide artificial respiration.
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
After swallowing
Do not induce vomiting; immediately call for medical help.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Product is not flammable. Use fire-fighting measures that suit the surrounding fire.
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Arsenic oxides (AS2Ox)
Advice for firefighters
Protective equipment:
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Ensure adequate ventilation
Environmental precautions:
Do not allow product to reach sewage system or any water course.
Methods and material for containment and cleaning up:
Dispose of contaminated material as waste according to section 13.
Ensure adequate ventilation.
Prevention of secondary hazards:
No special measures required.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Ensure good ventilation at the workplace.
Open and handle container with care.
Information about protection against explosions and fires:
The product is not flammable
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Do not store together with acids.
Store away from oxidizing agents.
Further information about storage conditions:
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
Properly operating chemical fume hood designed for hazardous chemicals and
having an average face velocity of at least 100 feet per minute.
Control parameters
Components with limit values that require monitoring at the workplace:
7440-38-2 Arsenic (100.0%)
PEL (USA) Long-term value: 0.5* 0.01** mg/m³
as As; *organic**inorg. compds.; 29 CFR 1910.1018
REL (USA) Ceiling limit value: 0.002 mg/m³
as As; 15min; See Pocket Guide App. A
TLV (USA) Long-term value: 0.01 mg/m³
as As; BEI
EL (Canada) Long-term value: 0.01 mg/m³
as As; ACIGH A1, IARC1
EV (Canada) Short-term value: 0.05 mg/m³
Long-term value: 0.01 mg/m³
as As
Ingredients with biological limit values:
7440-38-2 Arsenic (100.0%)
BEI (USA) 35 μg As/L
Medium: urine
Time: end of workweek
Parameter: Inorganic arsenic plus methylated metabolites (background)
Additional information:
No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Store protective clothing separately.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use self-contained respiratory protective device in emergency situations.
Recommended filter device for short term use:
Use a respirator with type P100 (USA) or P3 (EN 143) cartridges as a backup to engineering controls. Risk assessment should be performed to determine if air-purifying respirators are appropriate. Only use equipment tested and approved under appropriate government standards.
Protection of hands:
Impervious gloves
Check protective gloves prior to each use for their proper condition.
The selection of suitable gloves not only depends on the material, but also on quality. Quality will vary from manufacturer to manufacturer.
Material of gloves
Nitrile rubber, NBR
Penetration time of glove material (in minutes)
Glove thickness
0.11 mm
Eye protection:
Safety glasses
Body protection:
Protective work clothing


Information on basic physical and chemical properties
General Information
Form: Various forms (powder/flake/crystalline/beads, etc.)
Color: Grey
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 817 °C (1503 °F)
Boiling point/Boiling range: 614 °C (1137 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous)
Not determined.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure at 267 °C (513 °F): 0.01 hPa
Density at 20 °C (68 °F): 5.778 g/cm³ (48.217 lbs/gal)
Relative density
Not determined.
Vapor density
Not applicable.
Evaporation rate
Not applicable.
Solubility in / Miscibility with Water: Insoluble
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


No information known.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
Reacts with strong oxidizing agents
Conditions to avoid
No further relevant information available.
Incompatible materials:
Oxidizing agents
Hazardous decomposition products:
Arsenic oxides (As2Ox)


Information on toxicological effects
Acute toxicity:
Toxic if inhaled.
Toxic if swallowed.
The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity data for this substance.
LD/LC50 values that are relevant for classification:
No data
Skin irritation or corrosion:
May cause irritation
Eye irritation or corrosion:
May cause irritation
No sensitizing effects known.
Germ cell mutagenicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains mutation data for this substance.
EPA-A: human carcinogen: sufficient evidence from epidemiologic studies to support a causal association between exposure and cancer.
IARC-1: Carcinogenic to humans: sufficient evidence of carcinogenicity.
ACGIH A1: Confirmed human carcinogen: Agent is carcinogenic to
humans based on epidemiologic studies of, or convincing clinical evidence in, exposed humans.
Carcinogen as defined by OSHA.
NTP-K: Known to be carcinogenic: sufficient evidence from human studies.
The Registry of Toxic Effects of Chemical Substances (RTECS) contains tumorigenic and/or carcinogenic and/or neoplastic data for this substance.
Reproductive toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains reproductive data for this substance.
Specific target organ system toxicity - repeated exposure:
No effects known.
Specific target organ system toxicity - single exposure:
No effects known.
Aspiration hazard:
No effects known.
Subacute to chronic toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains multiple dose toxicity data for this substance.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.
Carcinogenic categories
OSHA-Ca (Occupational Safety & Health Administration)
Substance is listed


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Ecotoxical effects:
Very toxic for aquatic organisms
Additional ecological information:
General notes:
Do not allow product to reach ground water, water course or sewage system, even in small quantities.
Danger to drinking water if even extremely small quantities leak into the ground.
Also poisonous for fish and plankton in water bodies.
May cause long lasting harmful effects to aquatic life.
Avoid transfer into the environment.
Very toxic for aquatic organisms
Results of PBT and vPvB assessment
Not applicable.
Not applicable.
Other adverse effects
No further relevant information available.


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


UN proper shipping name
Transport hazard class(es)
6.1 Toxic substances.
6.1 (T5) Toxic substances
6.1 Toxic substances.
Packing group
Environmental hazards:
Environmentally hazardous substance, solid; Marine Pollutant
Special precautions for user
Warning: Toxic substances
EMS Number: F-A,S-A
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):
UN "Model Regulation":
UN1558, Arsenic, 6.1, II


Safety, health and environmental regulations/legislation specific for the substance or mixture
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
7440-38-2 Arsenic
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Arsenic Isotopes

Arsenic has one stable isotope: 75As.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
60As 59.99313(64)# UnKnown p to 59Ge 5+# N/A 454.22 -
61As 60.98062(64)# UnKnown p to 60Ge 3/2-# N/A 474.41 -
62As 61.97320(32)# UnKnown p to 61Ge 1+# N/A 489.01 -
63As 62.96369(54)# UnKnown p to 62Ge (3/2-)# N/A 506.4 -
64As 63.95757(38)# 40(30) ms [18(+43-7) ms] p to 63Ge 0+# N/A 520.07 -
65As 64.94956(32)# 170(30) ms ß+ to 64Ge 3/2-# N/A 535.6 -
66As 65.94471(73) 95.77(23) ms ß+ to 65Ge (0+) N/A 548.34 -
67As 66.93919(11) 42.5(12) s ß+ to 66Ge (5/2-) N/A 561.07 -
68As 67.93677(5) 151.6(8) s EC to 68Ge 3+ N/A 571.95 -
69As 68.93227(3) 15.2(2) min EC to 69Ge 5/2- 1.2 583.75 -
70As 69.93092(5) 52.6(3) min EC to 70Ge 4(+#) 2.1061 593.7 -
71As 70.927112(5) 65.28(15) h EC to 71Ge 5/2- 1.6735 604.57 -
72As 71.926752(5) 26.0(1) h EC to 72Ge 2- -2.1566 613.58 -
73As 72.923825(4) 80.30(6) d EC to 73Ge 3/2- N/A 624.45 -
74As 73.9239287(25) 17.77(2) d ß- to 74Se; EC to 74Ge 2- -1.597 632.53 -
75As 74.9215965(20) STABLE ß- to 76Se 3/2- -0.906 642.47 -
76As 75.922394(2) 1.0942(7) d - 2- 1.43947 649.62 100
77As 76.9206473(25) 38.83(5) h ß- to 77Se 3/2- N/A 659.56 -
78As 77.921827(11) 90.7(2) min ß- to 78Se 2- N/A 666.71 -
79As 78.920948(6) 9.01(15) min ß- to 79Se 3/2- N/A 675.72 -
80As 79.922534(25) 15.2(2) s ß- to 80Se 1+ N/A 681.94 -
81As 80.922132(6) 33.3(8) s ß- to 81Se 3/2- N/A 690.01 -
82As 81.92450(21) 19.1(5) s ß- to 82Se (1+) N/A 696.23 -
83As 82.92498(24) 13.4(3) s ß- to 83Se 3/2-# N/A 704.31 -
84As 83.92906(32)# 4.02(3) s ß- to 84Se; ß- + n to 83Se (3)(+#) N/A 707.73 -
85As 84.93202(21)# 2.021(10) s ß- + n to 84Se; ß- to 85Se (3/2-)# N/A 713.01 -
86As 85.93650(32)# 0.945(8) s ß- to 86Se; ß- + n to 85Se N/A N/A 717.37 -
87As 86.93990(32)# 0.56(8) s ß- to 87Se; ß- + n to 86Se 3/2-# N/A 722.65 -
88As 87.94494(54)# 300# ms [>300 ns] ß- to 88Se; ß- + n to 87Se N/A N/A 726.07 -
89As 88.94939(54)# 200# ms [>300 ns] ß- to 89Se 3/2-# N/A 729.49 -
90As 89.95550(86)# 80# ms [>300 ns] Unkown N/A N/A 731.98 -
91As 90.96043(97)# 50# ms [>300 ns] Unkown 3/2-# N/A 735.4 -
92As 91.96680(97)# 30# ms [>300 ns] Unkown N/A N/A 737.89 -