Californium (Cf)

From Wikipedia, the free encyclopediaCalifornium is a radioactive metallic chemical element with symbol Cf and atomic number 98. The element was first made in 1950 at the University of California Radiation Laboratory in Berkeley, by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium).

Californium in the periodic table

SymbolCf
Atomic number98
Group0
Period7
Blockf
Element categoryActinide

Physical properties

Phase at STPSolid
Density15.1 g/cm3
Atomic weight251 u
Melting point1173 K
899.85 °C
1651.73 °F
Boiling point1743 K
1469.85 °C
2677.73 °F

Atomära egenskaper

Electronegativity (Pauling Scale)1.3
Electron affinity-97.31 kJ/mol
Ionization energies
1608 kJ/mol

Electron configuration

Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f10 6s2 6p6 7s2
Electrons per shell2, 8, 18, 32, 28, 8, 2

History

Discovered1950
Discovered byLawrence Berkeley National Laboratory