Atomic Number Of Arsenic

Posted on 30-04-2021 by admin

Element Arsenic - As

Comprehensive data on the chemical element Arsenic is provided on this page; including scores of properties, element names in many languages, most known nuclides of Arsenic. Common chemical compounds are also provided for many elements. In addition technical terms are linked to their definitions and the menu contains links to related articles that are a great aid in one's studies.

The abundance of arsenic in the Earth’s crust is about five grams per ton; the cosmic abundance is estimated as about four atoms per million atoms of silicon. The element is widely distributed. A small amount exists in the native state, in 90–98 percent purity, generally in association with such metals as antimony and silver. Name: Arsenic Symbol: As Atomic Number: 33 Atomic Mass: 74.9216 amu Melting Point: 817.0 °C (1090.15 K, 1502.6 °F) Boiling Point: 613.0 °C (886.15 K, 1135.4 °F) Number of Protons/Electrons: 33 Number of Neutrons: 42 Classification: Metalloid Crystal Structure: Rhombohedral Density @ 293 K: 5.72 g/cm 3 Color: Gray Atomic Structure. Arsenic is a chemical element with symbol As and atomic number 33. Classified as a metalloid, Arsenic is a solid at room temperature.

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Overview of Arsenic

Atomic Number: 33
Group: 15
Period: 4
Series: Metalloids (Nonmetal)

Arsenic's Name in Other Languages

Latin: Arsenicum
Czech: Arzen
Croatian: Arsen
French: Arsenic
German: Arsenic - r
Italian: Arsenico
Norwegian: Arsen
Portuguese: Arsênio
Russian: Мышьяк
Spanish: Arsénico
Swedish: Arsenik

Atomic Structure of Arsenic

Atomic Radius: 1.33Å
Atomic Volume: 13.1cm³/mol
Covalent Radius: 1.2Å
Cross Section (Thermal Neutron Capture)σ_a/barns: 4.3
Crystal Structure: Rhombohedral
Electron Configuration:
1s² 2s²p⁶ 3s²p⁶d¹⁰ 4s²p³
Electrons per Energy Level: 2,8,18,5
Shell Model
Ionic Radius: 0.58Å
Filling Orbital: 4p³
Number of Electrons (with no charge): 33
Number of Neutrons (most common/stable nuclide): 42
Number of Protons: 33
Oxidation States:±3,5
Valence Electrons: 4s²p³
Electron Dot Model

Chemical Properties of Arsenic

Electrochemical Equivalent: 0.93177g/amp-hr
Electron Work Function: 3.75eV
Electronegativity: 2.18 (Pauling); 2.2 (Allrod Rochow)
Heat of Fusion: 369.9kJ/mol
Incompatibilities:
halogenated compounds, rhubidium, carbide
Ionization Potential
- First: 9.81
- Second: 18.633
- Third: 28.351
Valence Electron Potential (-eV): 74

Physical Properties of Arsenic

Atomic Mass Average: 74.92159
Boiling Point: 876K 603°C 1117°F
Coefficient of lineal thermal expansion/K^-1: 4.7E^-6
Conductivity
Electrical: 0.0345 10⁶/cm Ω
Thermal: 0.502 W/cmK
Density: 5.72g/cc @ 300K
Description:
Gray brittle non-metal flakes.
Enthalpy of Atomization: 301.3 kJ/mole @ 25°C
Enthalpy of Fusion: 24.44 kJ/mole
Enthalpy of Vaporization: 34.76 kJ/mole
Flammablity Class:
Freezing Point:see melting point
Hardness Scale
- Brinell: 1440 MN m^-2
- Mohs: 3.5
Heat of Vaporization: 34.76kJ/mol
Melting Point: 1081K 808°C 1486°F
Molar Volume: 13.08 cm³/mole
Optical Refractive Index: 1.001552
Physical State (at 20°C & 1atm): Solid
Specific Heat: 0.33J/gK

Regulatory / Health

CAS Number
- 7740-38-2
UN/NA ID and ERG Guide Number
- UN1557
RTECS: CG0525000
NFPA 704
- Health: 3
- Fire: 2
- Reactivity:
- Special Hazard:
OSHAPermissible Exposure Limit (PEL)
- TWA: 0.5 mg/m³
OSHA PEL Vacated 1989
NIOSHRecommended Exposure Limit (REL)
- No limits set by NIOSH
Routes of Exposure: Inhalation; Ingestion; Skin and/or eye contact
Target Organs: Skin, respiratory system, kidneys, central nervous system, liver, gastrointestinal tract, reproductive system
Levels In Humans:
Note: this data represents naturally occuring levels of elements in the typical human, it DOES NOT represent recommended daily allowances.
- Blood/mg dm^-3: 0.0017-0.09
- Bone/p.p.m: 0.08-1.6
- Liver/p.p.m: 0.023-1.61
- Muscle/p.p.m: 0.009-0.65
- Daily Dietary Intake: 0.04-1.4 mg
- Total Mass In Avg. 70kg human: 0.5-15 mg

Who / Where / When / How

Discoverer: Alberts Magna
Discovery Location: Unknown
Discovery Year: 1250
Name Origin:
Greek: arsenikos (male); Latin: arsenicum.
Abundance of Arsenic:
- Earth's Crust/p.p.m.: 1.5
- Seawater/p.p.m.:
  - Atlantic Suface: 0.00145
  - Atlantic Deep: 0.00153
  - Pacific Surface: 0.00145
  - Pacific Deep: 0.00175
- Atmosphere/p.p.m.: N/A
- Sun (Relative to H=1E¹²): N/A
Sources of Arsenic:
Found in mispickel (arsenopyrite). Mainly produced as a by-product of refining certain sulfide ores. Annual world wide production is around 47,000 tons (As2O3).
Uses of Arsenic:
Used as a deadly poison, in shotgun pellets, metal for mirrors, glass, lasers, light-emitting diodes (LED) and in semiconductors.
Additional Notes:
Arsenic is a carcinogen, associated with lung cancer when inhaled. Contact with skin can result in skin cancer. Also damage to intestines and liver. Toxic when ingested. Found in pesticides and wood preservatives. It is naturally occurring in many household products. It may have been known to ancient civilizations, but was probably first isolated by Magnus who lived between 1193-1280. Many sources reference 1250 as the year of discovery but this may be speculation.

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References

A list of reference sources used to compile the data provided on our periodic table of elements can be found on the main periodic table page.

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Arsenic is one of the most ancient element known to human history. It is very toxic and can enter the biological system through contaminated water, soil and air.

History and Discovery

Arsenic has a been known since prehistoric time and in the Bronze age it was used to make alloys with bronze. Arsenic was isolated as a distinct compound by Albertus Magnus in 1250. The word arsenic has been originated from zarnik, that means yellow or golden colored in Persian language and from Greek word arsenikon used for male. Later, the Greek word changed to arsenicum in French and finally the English word arsenic was derived from it. Arsenic has a notorious history in regard to its use as a fatal poison and was commonly termed as the poison of the kings and the king of the poisons [1].

Arsenic

Periodic Table Classification	Group 15 Period 4
State at 20C	Solid
Color	Metallic grey
Electron Configuration	[Ar] 3d10 4s2 4p3
Electron Number	33
Proton Number	33
Electron Shell	2, 8, 18, 5
Density	5.72 g.cm-3 at 20°C
Atomic number	23
Atomic Mass	74.92 g.mol -1
Electronegativity according to Pauling	2.18

Occurrence

Arsenic is abundant element and occurs in about 1.5ppm of concentration in the earth’s crust. It is categorized as the 53^rd most abundant element on earth. However, it is also present in minute quantities in water and atmosphere. Arsenic can exist in nature in its free elemental, as well as combined form. In combined form, it is primarily present in minerals of sulfur. There are various allotropic forms of arsenic, black, yellow and gray. The gray allotrope of arsenic is the most common and is widely used all over the world in various applications [2]. Arsenic is metabolized by some bacteria and certain animals, including goats, hamsters and chicken intake arsenic as an essential dietary nutrient. The largest producers of arsenic include China, Russia, Belgium, USA and Morocco.

Physical Characteristics

Yellow arsenic is waxy and soft. Both yellow and gray arsenic are highly volatile and unstable. They have very low density (5.727 g/cm³⁾. Black arsenic is brittle and have a glassy appearance. It is poor conductor of electricity.

Chemical Characteristics

When exposed to air it is tarnished and forms a golden-bronze layer on its surface that turns black with passage of time [3]. When arsenic is heated in air, it gives a pungent, garlic like odor as arsenic is oxidized to form arsenic trioxide. Certain compounds of arsenic undergo sublimation when exposed to high temperature, around 614 °C [3]. Arsenic reacts with various metals to form arsenides, and the most common oxidation state of arsenic in compounds is +3 and -3. There are various inorganic compounds of arsenic, including arsenic trioxide which is formed by the oxidation of arsenic in the presence of air and water. Arsenic also readily reacts with halogens to form trihalides and pentahalides, for instance arsenic pentafluoride. There are also many organic compounds of arsenic, such as cacodylic acid, which is formed by the methylation of arsenic trioxide, which is highly pungent and toxic compound.

Significance and Uses

The use of arsenic for various products was greatly limited due to the increased knowledge of its toxicity. In 2004, an official ban was applied on the use of chromated copper arsenate (CCA) in US and Europe. CCA was widely used as wood preservative in these countries. However, arsenic is still used in other countries of the world for wood preservation and various other applications.
Arsenic is used as a feed additive in swine and poultry industry, to improve the growth of animals.
Arsenic is used in various medial purposes, such as drugs for treatment of infection and cancer.
Arsenic is used to make alloys with lead to provide strength to lead batteries.

Health Hazards

Arsenic is toxic compound. Its toxicity to biological system and environment is greatly enhanced due to its water solubility. The main source of arsenic toxicity includes weathering of arsenic ores and mineral, and volcanic ash. Traces of arsenic pollution have been found in air, soil and water, from where it can be inhaled and ingested [4]. arsenic water pollution has reached to an alarming level in groundwater in Bangladesh and have according to an estimate, it has affected 57 million people living that region [5].

Isotopes of Arsenic

Natural arsenic has only one stable isotope, arsenic-75 [6]. There are around 33 artificially produced isotopes of arsenic, that range in atomic mass from 60 t0 92. The most stable radioactive isotope is arsenic-73, which as a half-life of 80 days.

REFERENCES

[1]. Vahidnia, A.; Van Der Voet, G. B.; De Wolff, F. A. (2007). “Arsenic neurotoxicity – a review”. Human & Experimental Toxicology. 26 (10): 823–32. doi:1177/0960327107084539. PMID18025055.

[2]. Norman, Nicholas C. (1998). Chemistry of Arsenic, Antimony and Bismuth. Springer. p. 50. ISBN978-0-7514-0389-3.

The Atomic Number Of Arsenic Is 33 What Is The Electron Configuration

[3]. Gokcen, N. A (1989). “The As (arsenic) system”. Bull. Alloy Phase Diagrams. 10: 11–22. doi:10.1007/BF02882166.

[4].Arsenic. The Agency for Toxic Substances and Disease Registry (2009).

[5]. Henke, Kevin R. (28 April 2009). Arsenic: Environmental Chemistry, Health Threats and Waste Treatment. p. 317. ISBN978-0-470-02758-5.