Cf
251.000Californium
Kaliforniyum
Californium is a synthetic radioactive actinide with atomic number 98. It is known for californium-252 neutron sources, reactor startup, neutron activation analysis, well logging and specialized neutron therapy research.
98
251 g/mol
[Rn] 5f¹⁰ 7s²
2 | 8 | 18 | 32 | 28 | 8 | 2
1.3
15.1 g/cm³
899.9 °C
1469.8 °C
Glenn T. Seaborg
Californium was synthesized in 1950 by Stanley Thompson, Kenneth Street Jr., Albert Ghiorso and Glenn Seaborg at Berkeley by bombarding curium with alpha particles. It was named after California and the University of California.
Californium-251
Half-life: About 898 years. Long-lived californium isotope.Californium-252
Half-life: About 2.65 years. Important spontaneous-fission neutron source isotope.Cf₂O₃
Californium(III) OxideResearch compound for californium chemistry.CfCl₃
Californium(III) ChlorideResearch compound for californium halide chemistry.- Californium-252 neutron sources for reactor startup and calibration
- Neutron activation analysis for material identification
- Oil-well and mineral exploration logging tools
- Portable neutron sources for security and industrial analysis
- Specialized neutron brachytherapy research and historical clinical use
Californium has no biological role. Its neutron-emitting isotopes, especially Cf-252, require heavy shielding and strict radiation controls.
- One microgram of Cf-252 emits about 2.3 million neutrons per second.
- Californium is among the most expensive elements because it must be made in specialized nuclear reactors.
- Cf-252 is valuable because it provides a compact neutron source without a reactor.
- Californium has atomic number 98 and symbol Cf.
- Its electron configuration is [Rn] 5f¹⁰ 7s².
- Californium commonly forms +3 compounds.
- Remember Cf-252 for neutron sources and spontaneous fission.
What is the atomic number of californium?
The atomic number of californium is 98.
What is the electron configuration of californium?
Californium has the electron configuration [Rn] 5f¹⁰ 7s².
What is californium used for?
Californium is used in neutron sources, reactor startup, neutron activation analysis, well logging and specialized research.
What is californium-252?
Californium-252 is a radioactive isotope that emits neutrons through spontaneous fission and has a half-life of about 2.65 years.
Why is californium expensive?
Californium is expensive because it is produced in tiny quantities by long irradiation processes in specialized nuclear reactors.