Arsenic (As)
"The Perfect Poison, a notorious villain from history, odorless and tasteless."
A memorable persona to anchor As in your mind.
5.727
Grams per cm³
616
Celsius (°C)
185
Radius (pm)
Daily Life Link
Arsenic is found as an ingredient in some insecticides and wood preservatives.
Discovery & History
Year Discovered
1250
Discovered By
Albertus Magnus
Origin of Name
"The name is thought to come from 'arsenikon', the Greek name for the yellow pigment orpiment."
Technical Properties
Atomic Mass
74.922 u
Standard State
solid
Boiling Point
616°C
Electron Configuration
[Ar] 3d104s24p3
1st Ionization Energy
9.815 eV
Electron Affinity
N/A
Oxidation States
"Arsenic is a brittle, steel-gray, semi-metallic solid."
Did You Know?
It has been nicknamed the "King of Poisons" and the "Poison of Kings" due to its discrete nature—it's colorless, odorless, and tasteless—making it a favorite for assassinations throughout history.
Despite its toxicity, arsenic-based compounds were historically used in medicines, including Salvarsan, the first effective treatment for syphilis.
A specific shade of green paint called Scheele's Green, made with arsenic, was very popular in the 19th century and is thought to have caused chronic poisoning, possibly even contributing to the death of Napoleon Bonaparte.
Some bacteria can 'breathe' arsenic, using it for respiration in the same way that humans use oxygen.