Arsenic
Metalloid
Arsenic (As) is a chemical element with atomic number 33, classified as a metalloid. At room temperature it is a solid. It was discovered in 1250 by Albertus Magnus.
Properties
- Atomic number
- 33
- Atomic mass
- 74.922 u
- Category
- Metalloid
- Group
- 15
- Period
- 4
- Block
- p-block
- Electron configuration
- [Ar] 3d¹⁰ 4s² 4p³
- Phase at STP
- Solid
- Density
- 5.776 g/cm³
- Melting point
- 1090 K (816.9 °C)
- Boiling point
- 887 K (613.9 °C)
- Electronegativity
- 2.18
- Atomic radius
- 114 pm
- Ionization energy
- 9.815 eV
- Discovery
- 1250 · Albertus Magnus
Common uses
Wood preservatives, semiconductors, pesticides, alloys
Did you know?
Notorious poison but also used in life-saving cancer treatments.