As
74.922Arsenic
Arsenik
Arsenic is a toxic metalloid with atomic number 33. It is known for arsenic poisoning, semiconductor compounds such as gallium arsenide, historical pigments, allotropes and environmental groundwater contamination.
33
74.922 g/mol
[Ar] 3d¹⁰ 4s² 4p³
2 | 8 | 18 | 5
2.18
5.727 g/cm³
816.9 °C
886.9 °C
Albertus Magnus
Arsenic compounds were known in antiquity as pigments and poisons. Metallic arsenic is often associated with Albertus Magnus in the 13th century, and arsenic later became famous in the history of toxicology and forensic chemistry.
Arsenic-75
Natural abundance: 100%. The only stable naturally occurring isotope of arsenic.As₂O₃
Arsenic TrioxideHighly toxic compound with controlled medical use in acute promyelocytic leukemia treatment.AsH₃
ArsineVery toxic gas used in semiconductor doping and specialty synthesis.As₂S₃
Arsenic TrisulfideOrpiment mineral, historical yellow pigment and infrared glass material.As₄S₄
RealgarRed-orange arsenic sulfide mineral historically used as pigment.GaAs
Gallium ArsenideIII-V semiconductor used in RF electronics, LEDs and solar cells.- Gallium arsenide semiconductors for electronics and optoelectronics
- Arsenic trioxide in specific cancer treatment protocols such as acute promyelocytic leukemia
- Historical pigments such as orpiment and realgar
- Specialty glass and semiconductor doping applications
- Lead alloy hardening in limited specialized uses
Arsenic has no confirmed essential role in humans. Inorganic arsenic is toxic and carcinogenic, while a few arsenic compounds have specialized medical uses under strict control.
- Arsenic-75 is monoisotopic, so natural arsenic has one stable isotope.
- Arsenic contamination of groundwater is a major environmental health problem in some regions.
- The Marsh test was an early forensic chemistry method for detecting arsenic.
- Gray arsenic is the most stable allotrope under ordinary conditions.
- Arsenic has atomic number 33 and belongs to group 15.
- Its electron configuration is [Ar] 3d¹⁰ 4s² 4p³.
- Arsenic is a metalloid and commonly shows oxidation states -3, +3 and +5.
- Toxicity depends strongly on chemical form; inorganic arsenic compounds are especially hazardous.
What is the atomic number of arsenic?
The atomic number of arsenic is 33.
What is the electron configuration of arsenic?
Arsenic has the electron configuration [Ar] 3d¹⁰ 4s² 4p³.
Is arsenic toxic?
Yes. Inorganic arsenic compounds are toxic and carcinogenic, so exposure must be carefully controlled.
What are the main allotropes of arsenic?
Important arsenic allotropes include gray arsenic, yellow arsenic and black arsenic.
What is gallium arsenide used for?
Gallium arsenide is a semiconductor used in RF electronics, LEDs, laser diodes and high-efficiency solar cells.
What is arsenic used for?
Arsenic is used in specialized semiconductors, controlled medical compounds, some historical pigments and limited alloy or glass applications.