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ELEMENT 098 · ACTINIDE

Californium · Cf Californium

Artificial radioactive elements, specific isotopes can be used as neutron sources.

atomic number / Atomic number
98
atomic weight / Atomic mass
251.07959 u
Family/Group
Actinium series (independent row)
Period · Block / Period · Block
7 · f
Category / Category
Actinium series · Actinide
State / State
solid state
Electron configuration
[Rn]7s2 5f10
Oxidation states / Oxidation states
+3
Electronegativity / Electronegativity
1.3(Pauling)
Density / Density
not included
Melting point / Melting point
1173 K
Boiling point / Boiling point
not included
Atomic radius / Atomic radius
245 pm(van der Waals)
First ionization energy
6.30 eV
Discovery year / Discovery
1950

attribute description and data source

properties taken from PubChem periodic table snapshot (2026-10-04). Atomic weights may be reference values ​​or representative isotope masses and cannot be considered exact constants for all samples; density, phase transition points, and phase states depend on temperature, pressure, and allotropes. The solidification of helium requires pressure. Some properties of radioactive and superheavy elements are predicted values, and missing items are marked as not included. Please check the original source and experimental conditions for precise calculations.

PubChem · Californiumoriginal information ↗

involves CaliforniumThe final phase of

current index collection 0strips. The reaction description is only used for knowledge query and material relationship understanding.

does not yet contain a reaction entry for this element; this does not mean that there are no known reactions for this element.