Periodic Table/Californium
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98Cf251 Da

Californium

Actinide·Period 7·f-block

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.

Gallery

A disc of californium metal (249Cf, 10 mg). The source implies that the disc has a diameter about twice the thickness of a typical pin, or on the order of 1 mm

United States Department of Energy (see File:Einsteinium.jpg), Public domain, via Wikimedia Commons

Bohr model of Californium

Physical Propertiesmass · density · phase · crystal

Atomic Mass

251Da

Density

15.1000g/cm³

Phase (STP)

Solid

Melting Point

1173.2K

Boiling Point

—

Molar Heat

—

Crystal Structure

—

Atomic Radiiatomic · covalent · van der Waals

Atomic (Empirical)

—

Covalent

168.00pm

Van der Waals

245.00pm

Electronic Propertieselectronegativity · ionization · affinity

Electron Configuration

[Rn] 5f10 7s2

Electron Shells

2, 8, 18, 32, 28, 8, 2

Electronegativity

—

Electron Affinity

—

1st Ionization Energy

6.3kJ/mol

Oxidation States

+2, +3, +4

Orbital DiagramAufbau · Hund's rule · Pauli exclusion

↑↓
1s2
↑↓
2s2
↑↓
↑↓
↑↓
2p6
↑↓
3s2
↑↓
↑↓
↑↓
3p6
↑↓
↑↓
↑↓
↑↓
↑↓
3d10
↑↓
4s2
↑↓
↑↓
↑↓
4p6
↑↓
↑↓
↑↓
↑↓
↑↓
4d10
↑↓
↑↓
↑↓
↑↓
↑↓
↑↓
↑↓
4f14
↑↓
5s2
↑↓
↑↓
↑↓
5p6
↑↓
↑↓
↑↓
↑↓
↑↓
5d10
↑↓
6s2
↑↓
↑↓
↑↓
6p6
↑↓
↑↓
↑↓
↑
↑
↑
↑
5f10
↑↓
7s2

Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f10 7s2Short: [Rn] 5f10 7s2

Ionization Energies (98 known)

1st6.3 kJ/mol2nd12.0 kJ/mol3rd22.4 kJ/mol4th37.7 kJ/mol5th51.9 kJ/mol6th75.0 kJ/mol7th91.0 kJ/mol8th112.9 kJ/mol9th133.0 kJ/mol10th152.0 kJ/mol11th178.0 kJ/mol12th201.0 kJ/mol13th225.0 kJ/mol14th247.0 kJ/mol15th265.0 kJ/mol16th286.0 kJ/mol17th310.0 kJ/mol18th334.0 kJ/mol19th368.0 kJ/mol20th390.0 kJ/mol21th536.0 kJ/mol22th566.0 kJ/mol23th597.0 kJ/mol24th630.0 kJ/mol25th662.0 kJ/mol26th695.0 kJ/mol27th744.0 kJ/mol28th778.0 kJ/mol29th814.0 kJ/mol30th847.0 kJ/mol31th1010.0 kJ/mol32th1050.0 kJ/mol33th1090.0 kJ/mol34th1120.0 kJ/mol35th1250.0 kJ/mol36th1300.0 kJ/mol37th1420.0 kJ/mol38th1470.0 kJ/mol39th1620.0 kJ/mol40th1700.0 kJ/mol41th1790.0 kJ/mol42th1880.0 kJ/mol43th1960.0 kJ/mol44th2050.0 kJ/mol45th2130.0 kJ/mol46th2220.0 kJ/mol47th2320.0 kJ/mol48th2410.0 kJ/mol49th2490.0 kJ/mol50th2580.0 kJ/mol51th2670.0 kJ/mol52th2750.0 kJ/mol53th3186.0 kJ/mol54th3261.0 kJ/mol55th3340.0 kJ/mol56th3424.0 kJ/mol57th3503.0 kJ/mol58th3581.0 kJ/mol59th3747.0 kJ/mol60th3828.0 kJ/mol61th3915.0 kJ/mol62th3998.0 kJ/mol63th4329.0 kJ/mol64th4407.0 kJ/mol65th4494.0 kJ/mol66th4570.0 kJ/mol67th5100.0 kJ/mol68th5190.0 kJ/mol69th5430.0 kJ/mol70th5520.0 kJ/mol71th8730.0 kJ/mol72th8900.0 kJ/mol73th9090.0 kJ/mol74th9290.0 kJ/mol75th9480.0 kJ/mol76th9660.0 kJ/mol77th10140.0 kJ/mol78th10330.0 kJ/mol79th10550.0 kJ/mol80th10740.0 kJ/mol81th11300.0 kJ/mol82th11470.0 kJ/mol83th11650.0 kJ/mol84th11820.0 kJ/mol85th13450.0 kJ/mol86th13660.0 kJ/mol87th14080.0 kJ/mol88th14280.0 kJ/mol89th29000.0 kJ/mol90th29500.0 kJ/mol91th30000.0 kJ/mol92th30500.0 kJ/mol93th36500.0 kJ/mol94th37100.0 kJ/mol95th37900.0 kJ/mol96th38443.5 kJ/mol97th150593.0 kJ/mol98th153124.0 kJ/molSuccessive Ionization Energies

Abundanceby mass

Biological Role

No biological role

Synthetic, radioactive element. No biological role.

Discovery

Discovered By

G.T.Seaborg, S.G.Tompson, A.Ghiorso, K.Street Jr.

Named By

—

Year

1950

Nuclear Data

Known Isotopes

20

Stable Isotopes

0

Stable Mass Numbers

None

Isotopes of Cf20 known

NuclideZNMass (AMU)Half-lifeDecayJπAbundance
237Cf98139237.062199800 msα (0.7%), SF (0.3%), β⁺5/2+—
238Cf98140238.06149021.1 msSF (0.975%), α (0.025%)0+—
239Cf98141239.06248228.0 sα (0.65%), β⁺5/2+—
254Cf98156254.08732460.5 dSF (0.9969%), α (0.0031%), 2β⁻0+—
255Cf98157255.0910461.42 hβ⁻ (1%), SF, α7/2+—
256Cf98158256.09344212.3 minSF (1%), α, 2β⁻0+—

Click any isotope for its full page with decay chain:

237Cf238Cf239Cf240Cf241Cf242Cf243Cf244Cf245Cf246Cf247Cf248Cf249Cf250Cf251Cf252Cf253Cf254Cf255Cf256Cf
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