Californium
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).
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
86 is the [Rn] core total across six shells.
At a glance
- Atomic number
- 98
- Atomic mass
- 251 u
- Phase
- Solid
- Density
- 15.1 g/cm³
- Melting point
- 1,173 K
- Boiling point
- 1,743 K
- First ionization energy
- 608 kJ/mol
- Electronegativity
- 1.3
- Electron affinity
- -97.31 kJ/mol
- Molar heat capacity
- Unavailable
- Period
- 7
- Appearance
- silvery
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.