As
Arsenic is a notorious metalloid historically known as the 'king of poisons'.
Physical Properties
| Atomic Mass | 74.922 u |
| Density | 5.776 g/cm³ |
| Melting Point | 1090.0 K |
| Boiling Point | 887.0 K |
| Appearance | Metallic gray |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 2.18 (Pauling) |
| 1st Ionization Energy | 947.0 kJ/mol |
| Electron Affinity | 78.2 kJ/mol |
| Oxidation States | -3, +2, +3, +5 |
Atomic Properties
| Electron Configuration | [Ar] 3d10 4s2 4p3 |
| Atomic Radius | 114.0 pm |
| Covalent Radius | 119.0 pm |
| Van der Waals Radius | 185.0 pm |
Discovery
| Discovered By | Albertus Magnus |
| Discovery Year | 1250 |
| Location | Germany |
| Named After | Greek 'arsenikon' meaning yellow orpiment |
About Arsenic
Arsenic occurs in many minerals and as a steel-gray, brittle solid. It sublimes rather than melting at standard pressure. Despite its toxicity, arsenic trioxide treats acute promyelocytic leukemia.
Uses & Applications
Semiconductors (gallium arsenide), wood preservatives, pesticides, lead alloys, and cancer treatment.
Fun Fact
Arsenic was the 'king of poisons' and 'poison of kings' -- a favored murder weapon in the Middle Ages because it was undetectable.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 75 | 1.0% | - | Yes |
Electron Configuration
[Ar] 3d10 4s2 4p3