Arsenic
Arsenic (砷, symbol As) is chemical element number 33, a Metalloid in period 4, group 15 of the periodic table, with a standard atomic weight of about 74.922. Metalloid known for its toxicity. Used historically as a pigment and pesticide.
Properties
| Atomic number | 33 |
|---|---|
| Symbol | As |
| Atomic mass | 74.922 u |
| Category | Metalloid |
| Period | 4 |
| Group | 15 |
| Electron configuration | [Ar] 3d¹⁰ 4s² 4p³ |
| Electronegativity | 2.18 |
| Covalent radius | 119 pm |
| Density | 5.776 g/cm³ |
| Melting point | 1090 K |
| Boiling point | 887 K |
| Discovery | Albertus Magnus, 1250 |
Overview
Metalloid known for its toxicity. Used historically as a pigment and pesticide. Element 33, Arsenic (As), is a Metalloid found in period 4, group 15. As a metalloid it shares properties of both metals and nonmetals and is a mainstay of semiconductor materials.
It has the configuration [Ar] 3d¹⁰ 4s² 4p³ and an electronegativity near 2.18; its 5 outer-shell electrons drive its bonding. Under standard conditions it exists as a solid; it melts near 1090 K (816.9 °C), boils near 887 K (613.9 °C), has a density around 5.776 g/cm³.
It is widely used in Electronics / Semiconductors and Agriculture / Fertiliser. On the safety side, it carries a high hazard rating. It was first described by Albertus Magnus in 1250. Use the comparison tool to line it up against other elements.
Electron shells
Electrons per shell: 2 · 8 · 18 · 5
Main uses
- Electronics / Semiconductors
- Agriculture / Fertiliser
Hazard
Compounds containing Arsenic
No compounds in this knowledge base contain Arsenic yet.
Data sources
Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.