Arsenic

33
As
Group
15
Period
4
Block
p
Protons
Electrons
Neutrons
33
33
42
General Properties
Atomic Number
33
Atomic Weight
74.9216
Mass Number
75
Category
Metalloids
Color
Silver
Radioactive
No
From the Latin word arsenicum, Greek arsenikon
Crystal Structure
Simple Trigonal
History
Greek historian Olympiodorus of Thebes roasted arsenic sulfide and obtained white arsenic during 5th century AD.

Albertus Magnus is believed to have been the first to isolate the element from a compound in 1250, by heating soap together with arsenic trisulfide.

In 1649, Johann Schröder published two ways of preparing arsenic.
Electrons per shell
2, 8, 18, 5
Electron Configuration
[Ar] 3d10 4s2 4p3
As
Prawns are known to contain quite high levels of arsenic
Physical Properties
Phase
Solid
Density
5.776 g/cm3
Melting Point
1090.15 K | 817 °C | 1502.6 °F
Boiling Point
876.15 K | 603 °C | 1117.4 °F
Heat of Fusion
27.7 kJ/mol
Heat of Vaporization
32.4 kJ/mol
Specific Heat Capacity
0.329 J/g·K
Abundance in Earth's crust
0.00021%
Abundance in Universe
8×10-7%
Ultrapure
Image Credits: Images-of-elements
Ultrapure metallic arsenic under argon
CAS Number
7440-38-2
PubChem CID Number
5359596
Atomic Properties
Atomic Radius
119 pm
Covalent Radius
119 pm
Electronegativity
2.18 (Pauling scale)
Ionization Potential
9.7886 eV
Atomic Volume
12.97 cm3/mol
Thermal Conductivity
0.502 W/cm·K
Oxidation States
-3, 2, 3, 5
Applications
The toxicity of arsenic to insects, bacteria and fungi led to its use as a wood preservative and as insecticides.

Arsenic is used in bronzing, pyrotechny, and for hardening and improving the sphericity of shot.

Gallium arsenide is a semiconductor used in laser diodes and LEDs.

Small amounts of arsenic can be used in lead alloys for ammunition.
Arsenic and its compounds are poisonous
Isotopes
Stable Isotopes
75As
Unstable Isotopes
60As, 61As, 62As, 63As, 64As, 65As, 66As, 67As, 68As, 69As, 70As, 71As, 72As, 73As, 74As, 76As, 77As, 78As, 79As, 80As, 81As, 82As, 83As, 84As, 85As, 86As, 87As, 88As, 89As, 90As, 91As, 92As