Californium - 98Cf: the essentials
- Name: californium
- Symbol: Cf
- Atomic number: 98
- Relative atomic mass (Ar): [ 251 ] (longest lived isotope)
- Standard state: solid at 298 K
- Appearance: unknown, but probably metallic and silvery white or grey in appearance
- Classification: Metallic
- Group in periodic table:
- Group name: Actinoid
- Period in periodic table: 7 (actinoid)
- Block in periodic table: f
- Shell structure: 22.214.171.124.28.8.2
- CAS Registry: 7440-71-3
Californium atoms have 98 electrons and the shell structure is 126.96.36.199.28.8.2. The ground state electronic configuration of neutral californium is [Rn].5f10.7s2 and the term symbol of californium is 5I8.
Californium is a radioactive rare earth metal named after the state of California and the University of California (USA). Californium-252 is a strong neutron emitter and one microgram emits 170 million neutrons per minute, making it a biological hazard. It has a few specialised uses but only a few of its compounds are known.
Californium: physical properties
- Density of solid: 15100 kg m-3
- Molar volume: 16.50 cm3
- Thermal conductivity: 10 (estimate) W m‑1 K‑1
Californium: heat properties
- Melting point: 1173 [900 °C (1652 °F)] K
- Boiling point: (no data) K
- Enthalpy of fusion: 20.5 kJ mol-1
Californium: atom sizes
- Atomic radius (empirical): (no data) pm
- Molecular single bond covalent radius: 168 (coordination number 3) ppm
- van der Waals radius: (no data) ppm
- Pauling electronegativity: 1.3 (Pauling units)
- Allred Rochow electronegativity: 1.2 (Pauling units)
- Mulliken-Jaffe electronegativity: (no data)
Californium: orbital properties
- First ionisation energy: 606.09 kJ mol‑1
- Second ionisation energy: 1160 kJ mol‑1
- Third ionisation energy: 2160 kJ mol‑1
- Universe: (no data) ppb by weight
- Crustal rocks: (no data) ppb by weight
- Human: (no data) ppb by weight
Californium: crystal structure
Californium: biological data
- Human abundance by weight: (no data) ppb by weight
Californium has no biological role.
Reactions of californium as the element with air, water, halogens, acids, and bases where known.
Californium: binary compounds
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of californium where known.
Californium: compound properties
Bond strengths; lattice energies of californium halides, hydrides, oxides (where known); and reduction potentials where known.
Californium: historyCalifornium was discovered by Glenn T. Seaborg, Stanley G. Thompson, Albert Ghiorso, Kenneth Street in 1950 at USA. Origin of name: named after the State and University of "California", USA.
Isolation: coming soon!