As
Arsenic
Atomic number: 33Mass: 74.922 uCategory: Metalloid
About Arsenic
Arsenic is a metalloid that can exist as several allotropes, the most common being grey arsenic. It is notorious as a poison, but small amounts are essential trace elements in some animals. Arsenic compounds are used in pesticides and semiconductors.
Properties
Period
4
Group
15
Block
P
Category
Metalloid
Electronegativity
2.18 (Pauling)
Ionization Energy
947 kJ/mol
Melting Point
1090 K (817°C)
Boiling Point
887 K (614°C)
Density
5.727 g/cm³
Oxidation States
-3, +3, +5
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p³
[Ar] 3d¹⁰ 4s² 4p³
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:5e⁻
Real-World Uses
Wood preservatives
Pesticides
Semiconductors (GaAs)
Glass manufacturing
Alloys
Fun Fact
Victorian wallpaper was often coloured with arsenic-based green pigment — breathing the fumes in damp houses was thought to have poisoned Napoleon Bonaparte!