Californium

Californium (Cf)

Californium is the 98th element in the periodic table and has a symbol of Cf and atomic number of 98. It has an atomic weight of (251) and a mass number of 237. Californium has ninety-eight protons and one hundred thirty-nine neutrons in its nucleus, and ninety-eight electrons in seven shells. It is located in group Actinides, period seven and block f of the periodic table. 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-
Animated Bohr Model of Cf (Californium)

Physical Properties

Atomic Radius
Molar Volume
Covalent Radius
168 pm
Metallic Radius
Ionic Radius
95 pm
Crystal Radius
109 pm
Van der Waals Radius
245 pm
Density
15.1 g/cm³

Chemical Properties

Energy
Proton Affinity
Electron Affinity
Ionization Energy
Ionization Energies of Cf (Californium)
Heat of Vaporization
Heat of Fusion
Heat of Formation
196 kJ/mol
Electrons
Electron Shells2, 8, 18, 32, 28, 8, 2
Bohr Model: Cf (Californium)
Valence Electrons2
Lewis Structure: Cf (Californium)
Electron Configuration[Rn] 5f10 7s2
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 5f10 7s2
Enhanced Bohr Model of Cf (Californium)
Orbital Diagram of Cf (Californium)
Oxidation States2, 3, 4, 5
Electronegativity
Electrophilicity Index
States of Matter
PhaseSolid
Gas Phase
Boiling Point
Melting Point
1,173.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual

Californium is a Colorless. Cf has a CPK of #ffffff, Jmol of #a136d4, and MOLCAS GV of #a136d4. The Appearance of Element 98 is silvery.

Color
Colorless
Appearancesilvery
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion
Molar Heat Capacity
Specific Heat Capacity
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type
Electrical Conductivity
Electrical Resistivity
Superconducting Point
Magnetism
Type
Magnetic Susceptibility (Mass)
Magnetic Susceptibility (Molar)
Magnetic Susceptibility (Volume)
Magnetic Ordering
Curie Point
Neel Point
Structure

The lattice angles of Californium are π/2, π/2, 2 π/3.

Crystal StructureSimple Hexagonal ()
Lattice Constant
Lattice Anglesπ/2, π/2, 2 π/3
Mechanical Properties
Hardness
Bulk Modulus
Shear Modulus
Young's Modulus
Poisson Ratio
Speed of Sound
Classification

The Glawe Number of Californium is 42. The Mendeleev Number of Cf is 32. The Pettifor Number of Element 98 is 39. The Goldschmidt Class of Californium (Cf) is synthetic.

CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number42
Mendeleev Number32
Pettifor Number39
Geochemical Class
Goldschmidt Classsynthetic

Other

The Dipole Polarizability of Californium is 122 plus or minus 20 a₀. The Allotropes of Cf is . The Neutron Cross Section of Element 98 is 2900. The Quantum Numbers of Californium (Cf) is 5I8. The Space Group of Californium is 194 (P63/mmc).

Gas Basicity
Dipole Polarizability
122 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
2,900
Neutron Mass Absorption
Quantum Numbers5I8
Space Group194 (P63/mmc)

Isotopes of Californium

Stable Isotopes0
Unstable Isotopes20
Natural Isotopes0

237Cf

Mass Number237
Neutron Number139
Relative Atomic Mass
237.062199272 ± 0.000104506 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
0.8 ± 0.2 s
Spin5/2
Quadrupole Moment
Discovery Year1995
Parity+

Decay ModeIntensity
α (α emission)70%
SF (spontaneous fission)30%
β+ (β+ decay; β+ = ϵ + e+)

238Cf

Mass Number238
Neutron Number140
Relative Atomic Mass
238.06149 ± 0.00032 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
21.1 ± 1.3 ms
Spin0
Quadrupole Moment
0
Discovery Year1995
Parity+

Decay ModeIntensity
SF (spontaneous fission)97.5%
α (α emission)2.5%

239Cf

Mass Number239
Neutron Number141
Relative Atomic Mass
239.062482 ± 0.000129 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
28 ± 2 s
Spin5/2
Quadrupole Moment
Discovery Year1981
Parity+

Decay ModeIntensity
α (α emission)65%
β+ (β+ decay; β+ = ϵ + e+)

240Cf

Mass Number240
Neutron Number142
Relative Atomic Mass
240.062253447 ± 0.00001936 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
40.3 ± 0.9 s
Spin0
Quadrupole Moment
0
Discovery Year1970
Parity+

Decay ModeIntensity
α (α emission)98.5%
SF (spontaneous fission)1.5%
β+ (β+ decay; β+ = ϵ + e+)

241Cf

Mass Number241
Neutron Number143
Relative Atomic Mass
241.06369 ± 0.00018 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
2.35 ± 0.18 m
Spin7/2
Quadrupole Moment
Discovery Year1970
Parity-

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)
α (α emission)15%

242Cf

Mass Number242
Neutron Number144
Relative Atomic Mass
242.063754544 ± 0.00001384 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
3.49 ± 0.15 m
Spin0
Quadrupole Moment
0
Discovery Year1967
Parity+

Decay ModeIntensity
α (α emission)61%
β+ (β+ decay; β+ = ϵ + e+)39%
SF (spontaneous fission)0.014%

243Cf

Mass Number243
Neutron Number145
Relative Atomic Mass
243.065475 ± 0.000194 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
10.8 ± 0.3 m
Spin1/2
Quadrupole Moment
0
Discovery Year1967
Parity+

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)86%
α (α emission)14%

244Cf

Mass Number244
Neutron Number146
Relative Atomic Mass
244.065999447 ± 0.000002809 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
19.5 ± 0.5 m
Spin0
Quadrupole Moment
0
Discovery Year1956
Parity+

Decay ModeIntensity
α (α emission)75%
ϵ (electron capture)25%

245Cf

Mass Number245
Neutron Number147
Relative Atomic Mass
245.068046755 ± 0.000002606 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
45 ± 1.5 m
Spin1/2
Quadrupole Moment
0
Discovery Year1956
Parity+

Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)64.7%
α (α emission)35.3%

246Cf

Mass Number246
Neutron Number148
Relative Atomic Mass
246.068803685 ± 0.000001625 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
35.7 ± 0.5 h
Spin0
Quadrupole Moment
0
Discovery Year1951
Parity+

Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)2.4%
ϵ (electron capture)

247Cf

Mass Number247
Neutron Number149
Relative Atomic Mass
247.070971348 ± 0.00001538 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
3.11 ± 0.03 h
Spin7/2
Quadrupole Moment
Discovery Year1954
Parity+

Decay ModeIntensity
ϵ (electron capture)99.965%
α (α emission)0.035%

248Cf

Mass Number248
Neutron Number150
Relative Atomic Mass
248.072182905 ± 0.000005497 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
333.5 ± 2.8 d
Spin0
Quadrupole Moment
0
Discovery Year1954
Parity+

Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)0.0029%

249Cf

Mass Number249
Neutron Number151
Relative Atomic Mass
249.074850428 ± 0.000001269 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
351 ± 2 y
Spin9/2
Quadrupole Moment
Discovery Year1954
Parity-

Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)5%

250Cf

Mass Number250
Neutron Number152
Relative Atomic Mass
250.076404494 ± 0.00000165 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
13.08 ± 0.09 y
Spin0
Quadrupole Moment
0
Discovery Year1954
Parity+

Decay ModeIntensity
α (α emission)99.923%
SF (spontaneous fission)0.077%

251Cf

Mass Number251
Neutron Number153
Relative Atomic Mass
251.079587171 ± 0.000004187 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
898 ± 44 y
Spin1/2
Quadrupole Moment
0
Discovery Year1954
Parity+

Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)

252Cf

Mass Number252
Neutron Number154
Relative Atomic Mass
252.081626507 ± 0.000002531 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
2.645 ± 0.008 y
Spin0
Quadrupole Moment
0
Discovery Year1954
Parity+

Decay ModeIntensity
α (α emission)96.8972%
SF (spontaneous fission)3.1028%

253Cf

Mass Number253
Neutron Number155
Relative Atomic Mass
253.085133723 ± 0.00000457 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
17.81 ± 0.08 d
Spin7/2
Quadrupole Moment
Discovery Year1954
Parity+

Decay ModeIntensity
β (β decay)99.69%
α (α emission)0.31%

254Cf

Mass Number254
Neutron Number156
Relative Atomic Mass
254.087323575 ± 0.000012304 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
60.5 ± 0.2 d
Spin0
Quadrupole Moment
0
Discovery Year1955
Parity+

Decay ModeIntensity
SF (spontaneous fission)99.69%
α (α emission)0.31%
(double β decay)

255Cf

Mass Number255
Neutron Number157
Relative Atomic Mass
255.091046 ± 0.000215 Da
G-Factor
Abundance
Radioactivity☢️ Radioactive
Half Life
85 ± 18 m
Spin7/2
Quadrupole Moment
Discovery Year1981
Parity+

Decay ModeIntensity
β (β decay)100%
SF (spontaneous fission)
α (α emission)

256Cf

Mass Number256
Neutron Number158
Relative Atomic Mass
256.093442 ± 0.000338 Da
G-Factor
0
Abundance
Radioactivity☢️ Radioactive
Half Life
12.3 ± 1.2 m
Spin0
Quadrupole Moment
0
Discovery Year1980
Parity+

Decay ModeIntensity
SF (spontaneous fission)100%
α (α emission)
(double β decay)
Californium

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
Etymology (Name Origin)Named after the state and University of California.
Pronunciationkal-eh-FOR-ni-em (English)
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.

Abundance
Abundance in Earth's crust
Natural Abundance (Oceans)
Natural Abundance (Human Body)
0 %
Natural Abundance (Meteor)
0 %
Natural Abundance (Sun)
0 %
Abundance in Universe
0 %

Nuclear Screening Constants

Also Known As

  • Cf
  • element 98
  • 98Cf

Translations

  • Frenchcalifornium
  • GermanCalifornium
  • Amharicካሊፎርኒየም
  • Arabicكاليفورنيوم
  • AzerbaijaniKalifornium
  • BelarusianКаліфорній
  • Banglaক্যালিফোর্নিয়াম
  • Bosniankalifornij
  • Catalancaliforni
  • CorsicanCaliforniu
  • Czechkalifornium
  • ChuvashКалифорни
  • WelshCalifforniwm
  • Danishcalifornium
  • Greekκαλιφόρνιο
  • Esperantokaliforniumo
  • Spanishcalifornio
  • Estoniankalifornium
  • Basquekalifornio
  • Persianکالیفرنیم
  • Finnishkalifornium
  • FriulianCaliforni
  • IrishCalafoirniam
  • GalicianCalifornio
  • ManxCalifornium
  • Hakka Chinesecalifornium
  • Hebrewקליפורניום
  • Fiji HindiCalifornium
  • Croatiankalifornij
  • Haitian CreoleKalifònyòm
  • Hungariankalifornium
  • Armenianկալիֆոռնիում
  • Interlinguacalifornium
  • Indonesiankalifornium
  • Idokalifornio
  • Italiancalifornio
  • Japaneseカリホルニウム
  • Lojbanjinmrkaliforni
  • JavaneseKalifornium
  • Korean캘리포늄
  • KomiКалифорний
  • Latincalifornium
  • LuxembourgishCalifornium
  • LigurianCalifornio
  • Lithuaniankalifornis
  • Latviankalifornijs
  • Malayalamകാലിഫോർണിയം
  • Marathiकॅलिफोर्नियम
  • Western MariКалифорний
  • MalayKalifornium
  • Burmeseကာလီဖိုနီယမ်
  • Dutchcalifornium
  • Norwegian Nynorskcalifornium
  • Occitancalifòrni
  • Polishkaliforn
  • Portuguesecalifórnio
  • QuechuaKalifornyu
  • Romaniancaliforniu
  • Russianкалифорний
  • Sanskritकालिफोर्नियम
  • YakutКалифорниум
  • Siciliancaliforniu
  • Serbo-CroatianKalifornijum
  • Slovakkalifornium
  • Sloveniankalifornij
  • Albaniankaliforniumi
  • Serbianкалифорнијум
  • Saterland FrisianCalifornium
  • Swedishcalifornium
  • Thaiแคลิฟอร์เนียม
  • Turkishkaliforniyum
  • Uyghurكالىفورنىي
  • Ukrainianкаліфорній
  • Urduکیلیفورنیئم
  • VepsKalifornii
  • Vietnamesecaliforni
  • WarayCalifornyo
  • KalmykКалифорниүм
  • YorubaKalifọ́rníọ̀m
  • Chinese
  • Norwegian Bokmålcalifornium
  • CebuanoCalifornyo
  • Macedonianкалифорниум
  • Central Kurdishکالیفۆرنیۆم
  • Western Panjabiکیلیفورنیم
  • BretonKaliforniom
  • German (Switzerland)Californium
  • English (Canada)Californium
  • English (United Kingdom)californium
  • Portuguese (Brazil)califórnio
  • Cantonese
  • Odiaକାଲିଫର୍ମିଅମ
  • Gujaratiકેલિફોર્નીયમ
  • Tamilகலிபோர்னியம்
  • TatarКалифорний
  • Bulgarianкалифорний
  • PiedmonteseCalifòrni
  • Newariक्यालिफोर्नियम
  • Kannadaಕ್ಯಾಲಿಫೋರ್ನಿಯಮ್
  • KazakhКалифорний
  • Belarusian (Taraskievica orthography)Каліфорн
  • UzbekKaliforniy
  • AromanianCaliforniu
  • Nepaliक्यालिफोर्नियम
  • KyrgyzКалифорний
  • Teluguకాలిఫోర్నియం
  • Maltesekalifornju
  • Chinese (Simplified)
  • Hindiकैलीफोर्नियम
  • Scottish GaelicCalafòrnium
  • Paliक्यालिफोर्नियम
  • cdoCalifornium
  • Min Nan ChineseCalifornium
  • FaroeseKalifornium
  • AsturianCalifornio
  • LimburgishCalifornium
  • Bhojpuriकैलिफोर्नियम
  • Chinese (Traditional)
  • Chinese (Macao SAR China)
  • Chinese (China)
  • Chinese (Hong Kong SAR China)
  • Chinese (Malaysia)
  • Chinese (Singapore)
  • Chinese (Taiwan)
  • Lingua Franca Novacalifornio
  • TagalogKalipornyo
  • AfrikaansKalifornium
  • kbpKalɩfɔrnɩyɔm
  • Literary Chinese
  • Northern FrisianKalifornium
  • Volapükkalifornin
  • oloKalifornii
  • TajikКалифорний
  • Georgianკალიფორნიუმი
  • Mongolianкалифорни
  • Wu Chinese
  • SardinianCalifòrniu
  • SwahiliKaliforni
  • Moroccan Arabicكاليفورنيوم
  • BashkirКалифорний
  • Egyptian Arabicكاليفورنيوم
  • Pashtoکاليفورنيوم
  • CornishKaliforniom
  • BalineseKalifornium
  • ZuluUmNgcalife