CAS Number7440-05-3
PubChem CID23938
Atomic Radius137
Atomic Volume8.9
Atomic Weight106.42
Boiling Point2,963
Bulk Modulus
CategoryTransition metals
Crystal StructureFace Centered Cubic
Covalent Radius139
Electrical Resistivity
Electron Configuration[Kr] 4d10
Electrons per shell2, 8, 18, 18
Heat of Fusion16.7
Heat of Vaporization380
Ionization Potential8.337
Magnetic Ordering
Magnetic Susceptibility
Mass Number46
Melting Point1,554.9
Atomic Number106
Oxidation States2, 4
Poisson Ratio
Shear Modulus
Specific Heat Capacity0.244
Thermal Conductivity0.718
Van der Waals radius
Young's Modulus
Abundance in Earth's crust6.3×10-7%
Abundance in Universe2×10-7%
Pd Palladium 46 106.42 10 5 d 46 1554.0 3140.0 [Kr] 4d10 2 8 18 18 0 12.0 6.3E-7% Silver Cubic: Face centered 2.2 1.58 {"1":"804.4","2":"1870","3":"3177"} 804 53.7 131 +2,4 1.37 8.9 16.74 393.3 0.244 71.8 0 Solid, Paramagnetic, Conductor, TransitionMetal, Metal, Stable, Natural peh-LAY-di-em Soft, malleable, ductile, silvery-white metal. Used as a substitue for silver in dental items and jewelry. The pure metal is used as the delicate mainsprings in analog wristwatches. Also used in surgical instruments and as catalyst . Obtained with platinum, nickel, copper and mercury ores. ZAyKx0m97WA Palladium
Selenium was first observed in about the year 1300 by the alchemist Arnold of Villanova.

Selenium was discovered in 1817 by Jöns Jacob Berzelius and Johan Gottlieb Gahn who noted the similarity of the new element to the previously-known tellurium.

In 1873, Willoughby Smith found that the electrical resistance of grey selenium was dependent on the ambient light. From the Greek word Selene, moon 46 1803 William Hyde Wollaston England Named after the asteroid "Pallas" which was discovered at about the same time and from the Greek name "Pallas", goddess of wisdom

Isotopes of Selenium

Standard Atomic Weight


Stable Isotopes

102Pd 104Pd 105Pd 106Pd 108Pd 110Pd

Unstable Isotopes

91Pd 92Pd 93Pd 94Pd 95Pd 96Pd 97Pd 98Pd 99Pd 100Pd 101Pd 103Pd 107Pd 109Pd 111Pd 112Pd 113Pd 114Pd 115Pd 116Pd 117Pd 118Pd 119Pd 120Pd 121Pd 122Pd 123Pd 124Pd

Many of selenium's compounds, such as selenates and selenites, are highly toxic
Selenium deficiency in animals can lead to slow growth
Selenium is used in the glass industry to decolorize glass and to make red-colored glasses and enamels.

It is used as a catalyst in many chemical reactions.

It is also used as a photographic toner, and as an additive to stainless steel.

Selenium sulfide is used in anti-dandruff shampoos.