Arsenic

Arsenic Element Properties

p32
Ge
Germanium
p33
As
Arsenic
p34
Se
Selenium
General
NameArsenic
SymbolAs
Number33
Group Number15
GroupNon-Metal, Nitrogen group
Blockp
Density5.72 g/cm3
Atomic Weight74.9216 g/mol
Atomic Volume13.1 cm3/mol
Discover1600


States
StateSolid
Melting Point1090 K
Boiling Point887 K
Triple PointNil
Critical Point1673 K
Heat of Fusion24.44 kJ/mol
Heat of Vaporization34.76 kJ/mol


Energies
First Ionization Energy946.5 kJ/mole
Second Ionization Energy1797.8 kJ/mole
Third Ionization Energy2735.4 kJ/mole
Electronegativity2.18
Electron Affinity78 kJ/mole
Specific Heat0.33 J/gK
Heat Atomization302 kJ/mole atoms


Oxidation and Electrons
Shells2,8,18,5
Electron Configuration[Ar] 3d10 4s2 4p3
Minimum Oxidation Number-3
Maximum Oxidation Number5
Minimum Common Oxidation Number-3
Maximum Common Oxidation Number5


Appearance and Characteristics
Crystal Structurerhombohedral
Characteristicssemimetal, brittle, 3 forms
Colorgray
Usesphotocells (GaAs), poisons
Hardness3.5 mohs
ToxicityNone


Reactions
Reaction with Airmild, w/ht =>As4O6
Reaction with 6M HClNone
Reaction with 15M HNO3mild, w/ht =>H3AsO4, NOx
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes1
HydrideAsH3
OxideAs2O3
ChlorideAsCl3 AsCl5


Radius
Atomic Radius120 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)72 pm


Conductivity
Thermal Conductivity50.2 J/m-sec-deg
Electrical Conductivity30.03 1/mohm-cm
Polarizability4.3 A3


Abundance
SourceArsenopyrite, enargite (misc)
Relation Abundance Solar System0.817 log
Abundance Earth's Crust0.3 log


p32
Ge
Germanium
p33
As
Arsenic
p34
Se
Selenium