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Californium (Cf)

Atomic number: 98 · Category: actinide · Group 3 · Period 7 · Phase: Solid

Californium 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).

Atomic mass: 251
Density: 15.1
Melting point: 1173 K
Boiling point: 1743 K
Appearance: silvery
Source: Wikipedia
Block: f
CPK color:#a136d4

Electronic structure

Electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f10
Configuration (semantic): [Rn] 5f10 7s2
Shells: 2, 8, 18, 32, 28, 8, 2
Electronegativity (Pauling): 1.3
Electron affinity: -97.31
Ionization energies: 608

Periodic position

Group: 3
Period: 7
xpos: 12
ypos: 10

Spectral/Bohr images

Image
A disc of californium metal (249Cf, 10 mg). The source implies that the disc has a diameter about twice the thickness of a typical pin, or on the order of 1 mm
3D Model