Periodic Table/Einsteinium
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99Es252 Da

Einsteinium

Actinide·Period 7·f-block

Appearance is unknown, however it is most probably metallic and silver or gray in color. Radioactive metallic transuranic element belonging to the actinoids. Es-254 has the longest half-life of the eleven known isotopes at 270 days. First identified by Albert Ghiorso and associates in the debris of the 1952 hydrogen bomb explosion. In 1961 the first microgram quantities of Es-232 were separated. While einsteinium never exists naturally, if a sufficient amount was assembled, it would pose a radiation hazard.

Gallery

300 micrograms of Einsteinium 253, which has a half-life of 20 days.

Haire, R. G., US Department of Energy.Touched up by Materialscientist at en.wikipedia., Public domain, via Wikimedia Commons

Bohr model of Einsteinium

Physical Propertiesmass · density · phase · crystal

Atomic Mass

252Da

Density

8.8400g/cm³

Phase (STP)

Solid

Melting Point

1133.2K

Boiling Point

—

Molar Heat

—

Crystal Structure

—

Atomic Radiiatomic · covalent · van der Waals

Atomic (Empirical)

—

Covalent

165.00pm

Van der Waals

245.00pm

Electronic Propertieselectronegativity · ionization · affinity

Electron Configuration

[Rn] 5f11 7s2

Electron Shells

2, 8, 18, 32, 29, 8, 2

Electronegativity

—

Electron Affinity

—

1st Ionization Energy

6.4kJ/mol

Oxidation States

+2, +3

Orbital DiagramAufbau · Hund's rule · Pauli exclusion

↑↓
1s2
↑↓
2s2
↑↓
↑↓
↑↓
2p6
↑↓
3s2
↑↓
↑↓
↑↓
3p6
↑↓
↑↓
↑↓
↑↓
↑↓
3d10
↑↓
4s2
↑↓
↑↓
↑↓
4p6
↑↓
↑↓
↑↓
↑↓
↑↓
4d10
↑↓
↑↓
↑↓
↑↓
↑↓
↑↓
↑↓
4f14
↑↓
5s2
↑↓
↑↓
↑↓
5p6
↑↓
↑↓
↑↓
↑↓
↑↓
5d10
↑↓
6s2
↑↓
↑↓
↑↓
6p6
↑↓
↑↓
↑↓
↑↓
↑
↑
↑
5f11
↑↓
7s2

Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f11 7s2Short: [Rn] 5f11 7s2

Ionization Energies (99 known)

1st6.4 kJ/mol2nd12.2 kJ/mol3rd22.7 kJ/mol4th38.8 kJ/mol5th54.1 kJ/mol6th71.0 kJ/mol7th97.0 kJ/mol8th112.9 kJ/mol9th137.0 kJ/mol10th157.0 kJ/mol11th180.0 kJ/mol12th206.0 kJ/mol13th231.0 kJ/mol14th252.0 kJ/mol15th270.0 kJ/mol16th294.0 kJ/mol17th317.0 kJ/mol18th342.0 kJ/mol19th367.0 kJ/mol20th398.0 kJ/mol21th421.0 kJ/mol22th576.0 kJ/mol23th606.0 kJ/mol24th638.0 kJ/mol25th672.0 kJ/mol26th705.0 kJ/mol27th738.0 kJ/mol28th790.0 kJ/mol29th824.0 kJ/mol30th861.0 kJ/mol31th895.0 kJ/mol32th1060.0 kJ/mol33th1100.0 kJ/mol34th1140.0 kJ/mol35th1180.0 kJ/mol36th1310.0 kJ/mol37th1360.0 kJ/mol38th1480.0 kJ/mol39th1530.0 kJ/mol40th1690.0 kJ/mol41th1780.0 kJ/mol42th1870.0 kJ/mol43th1950.0 kJ/mol44th2040.0 kJ/mol45th2130.0 kJ/mol46th2220.0 kJ/mol47th2300.0 kJ/mol48th2410.0 kJ/mol49th2490.0 kJ/mol50th2580.0 kJ/mol51th2680.0 kJ/mol52th2760.0 kJ/mol53th2850.0 kJ/mol54th3294.0 kJ/mol55th3370.0 kJ/mol56th3449.0 kJ/mol57th3535.0 kJ/mol58th3616.0 kJ/mol59th3694.0 kJ/mol60th3866.0 kJ/mol61th3947.0 kJ/mol62th4038.0 kJ/mol63th4120.0 kJ/mol64th4456.0 kJ/mol65th4537.0 kJ/mol66th4620.0 kJ/mol67th4700.0 kJ/mol68th5260.0 kJ/mol69th5350.0 kJ/mol70th5600.0 kJ/mol71th5690.0 kJ/mol72th8960.0 kJ/mol73th9140.0 kJ/mol74th9330.0 kJ/mol75th9530.0 kJ/mol76th9720.0 kJ/mol77th9910.0 kJ/mol78th10400.0 kJ/mol79th10590.0 kJ/mol80th10810.0 kJ/mol81th11010.0 kJ/mol82th11570.0 kJ/mol83th11740.0 kJ/mol84th11930.0 kJ/mol85th12110.0 kJ/mol86th13810.0 kJ/mol87th14030.0 kJ/mol88th14460.0 kJ/mol89th14700.0 kJ/mol90th29700.0 kJ/mol91th30100.0 kJ/mol92th30700.0 kJ/mol93th31100.0 kJ/mol94th37400.0 kJ/mol95th38100.0 kJ/mol96th38900.0 kJ/mol97th39451.4 kJ/mol98th154344.0 kJ/mol99th156927.0 kJ/molSuccessive Ionization Energies

Abundanceby mass

Biological Role

No biological role

Synthetic, radioactive element. No biological role.

Discovery

Discovered By

Argonne, Los Alamos, U of Calif

Named By

—

Year

1952

Nuclear Data

Known Isotopes

20

Stable Isotopes

0

Stable Mass Numbers

None

Isotopes of Es20 known

NuclideZNMass (AMU)Half-lifeDecayJπAbundance
239Es99140239.068310Unknownα, β⁺, SF3/2-—
240Es99141240.0689496.00 sα (0.7%), β⁺ (0.3%), β⁺SF (0.0016%)4-—
241Es99142241.0685925.10 sα (1%), β⁺3/2-—
256Es99157256.0935977.60 hβ⁻ (1%), β⁻SF (0.00002%)7+—
257Es99158257.0959797.70 dβ⁻ (1%), α7/2+—
258Es99159258.099520Unknownβ⁻, α——

Click any isotope for its full page with decay chain:

239Es240Es241Es242Es243Es244Es245Es246Es247Es248Es249Es250Es251Es252Es253Es254Es255Es256Es257Es258Es
Wikipedia →Data: Bowserinator · IAEA NDS · mendeleev