Stable isotope Arsenic (As)

Isotope Z(p) N(n) Atomic Mass Natural Abundance Nuclear Spin
As-75 33 42 74.921597 100.00% 3/2-

Properties of Arsenic

Name Arsenic
Symbol As
Atomic number 33
Atomic weight 74.9216
Standard state Solid at 298 °K
CAS Registry ID 7440-38-2
Group in periodic table 15
Group name Pnictogen
Period in periodic table 4
Block in periodic table p-block
Color Metallic gray
Classification Semi-metallic
Melting point 817 °C at 28 atm
Boiling point 613 °C subl.
Thermal conductivity 50 W/(m·K)
Electrical resistivity 33.3 µΩ·cm at 20 °C
Electronegativity 2.18
Specific heat 328 J/(kg·K)
Heat of vaporization 32.4 kJ·mol-1
Heat of fusion 27.7 kJ·mol-1
Density of liquid 5.22 g/cm-3 at 817 °C
Density of solid 5.727 g/cm3 
Covalent radius As3+ :1.21 Å
Electron configuration [Ar]4s23d104p3
Principal oxidation states -3, 0, +3, +5