Californium

Californium (Cf)

Radioactive metallic transuranic element. Belongs to actinoid series. Cf-251 has a half life of about 700 years. Nine isotopes are known. Cf-252 is an intense Neutron source, which makes it an intense Neutron source and gives it a use in Neutron activation analysis and a possible use as a radiation source in medicine. First produced by Glenn T. Seaborg and associates in 1950.
Atomic Number98
Atomic Weight251
Mass Number237
Group
Period7
Blockf
Protons98 p+
Neutrons139 n0
Electrons98 e-
Californium.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
Atomic Volume
Covalent Radius
168 pm
Metallic Radius
Ionic Radius
95 pm
Crystal Radius
109.00000000000001 pm
Van der Waals radius
245.00000000000003 pm
Density
15.1 g/cm³
Boiling Point
Melting Point
900 K
Electrons per shell2, 8, 18, 32, 28, 8, 2
Electronegativity
Electrophilicity
Proton Affinity
Electron Affinity
Ionization Potential
Heat of Vaporization
Heat of Fusion
Heat of Formation
196 kJ/mol
Molar Heat Capacity
Specific Heat Capacity
Thermal Conductivity
Gas Basicity
Dipole Polarizability
122 a₀
C6 Dispersion Coefficient
Oxidation States2, 3, 4
Color
Colorless
Crystal StructureSimple Hexagonal ()
Lattice Constant
Bulk Modulus
Electrical Resistivity
Electron Configuration[Rn] 5f10 7s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number42
Mendeleev Number32
Pettifor Number39
Geochemical Class
Goldschmidt Classsynthetic
Radioactivity
RadioactiveYes ☢️
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universena

Isotopes of Californium

Stable Isotopes
Unstable Isotopes
237Cf 238Cf 239Cf 240Cf 241Cf 242Cf 243Cf 244Cf 245Cf 246Cf 247Cf 248Cf 249Cf 250Cf 251Cf 252Cf 253Cf 254Cf 255Cf 256Cf

History

Californium was discovered by Stanley G. Thompson, Kenneth Street, Jr., Albert Ghiorso and Glenn T. Seaborg in 1950 at the University of California, Berkeley. It was produced by the bombardment of curium with alpha particles. Californium was isolated in macro quantities for the first time by Burris Cunningham and Stanley Thompson in 1958. Named after California and the University of California

DiscoverersG.T.Seaborg, S.G.Tompson, A.Ghiorso, K.Street Jr.
Discovery LocationUnited States
Discovery Year1950
Name OriginNamed after the state and University of California.
Californium is harmful due to its radioactivity
Californium is produced in nuclear reactors and particle accelerators

Uses

Californium is used as a portable neutron source for discovery of metals such as gold or silver by on-the-spot activation analysis. Neutrons from californium are employed as a treatment of certain cervical and brain cancers where other radiation therapy is ineffective. Neutron moisture gauges use californium-252 to find water and petroleum layers in oil wells. It has no significant commercial applications.

Sources

Made by bombarding curium with helium ions.