CAS Number7440-46-2
PubChem CID5354618
Atomic Radius265
Atomic Volume71.07
Atomic Weight132.905
Boiling Point671
Bulk Modulus
CategoryAlkali metals
Crystal StructureBody Centered Cubic
Covalent Radius244
Electrical Resistivity
Electron Configuration[Xe] 6s1
Electrons per shell2, 8, 18, 18, 8, 1
Heat of Fusion2.09
Heat of Vaporization65
Ionization Potential3.894
Magnetic Ordering
Magnetic Susceptibility
Mass Number55
Melting Point28.44
NameSiżjum, ²Ċesju
Atomic Number133
Oxidation States-1, 1
Poisson Ratio
Shear Modulus
Specific Heat Capacity0.242
Thermal Conductivity0.359
Van der Waals radius
Young's Modulus
Abundance in Earth's crust0.00019%
Abundance in Universe8×10-8%
Cs Siżjum, ²Ċesju 55 132.9054519 1 6 s 55 28.4 669.0 [Xe] 6s1 2 8 18 18 8 1 1.87 0.00019% Silver Cubic: Body centered 0.8 0.659 {"1":"375.7","2":"2234.3","3":"3400"} 382 45.5 225 1 2.67 70.0 2.092 67.74 0.24 35.9 0 Solid, Conductor, AlkaliMetal, Metal, Stable, Natural SEE-zi-em Very soft, light gray, ductile metal. Used as a 'getter' to remove air traces in vacuum and cathode-ray tubes. Also used in producing photoelectric devices and atomic clocks. Since it ionizes readily, it is used as an ion rocket motor propellant. Found in pollucite [(Cs4Al4Si9O26).H2O] and as trace in lepidolite. 5aD6HwUE2c0 Cesium
Molybdenite was often confused for graphite and it was thought to contain lead.

In 1778 Swedish scientist Carl Wilhelm Scheele proved that molybdenite was not graphite nor did it contain lead.

In 1781, Scheele's friend and countryman, Peter J. Hjelm isolated the metal by using carbon and linseed oil. From the Greek word molybdo, lead 55 1860 Gustav Kirchhoff, Robert Bunsen Germany From the Latin word "caesius" meaning "sky blue" or "heavenly blue"

Isotopes of Molybdenum

Standard Atomic Weight


Stable Isotopes


Unstable Isotopes

112Cs 113Cs 114Cs 115Cs 116Cs 117Cs 118Cs 119Cs 120Cs 121Cs 122Cs 123Cs 124Cs 125Cs 126Cs 127Cs 128Cs 129Cs 130Cs 131Cs 132Cs 134Cs 135Cs 136Cs 137Cs 138Cs 139Cs 140Cs 141Cs 142Cs 143Cs 144Cs 145Cs 146Cs 147Cs 148Cs 149Cs 150Cs 151Cs

Molybdenum is toxic in all but small quantities
Molybdenum is essential for plant foliage health
Molybdenum is used as glass furnace electrodes due to its high melting point.

The metal is also used in nuclear energy applications and for missile and aircraft parts.

Molybdenum is valuable as a catalyst in the refining of petroleum.

Molybdenum is used in small quantities to harden steel and is used in many alloys.