Einsteinium

Einsteinium (Es)

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.
Atomic Number99
Atomic Weight252
Mass Number239
Group
Period7
Blockf
Protons99 p+
Neutrons140 n0
Electrons99 e-
Einsteinium.jpg Animated Bohr Model of Es (Einsteinium) Enhanced Bohr Model of Es (Einsteinium) Bohr Model: Es (Einsteinium) Orbital Diagram of Es (Einsteinium)

Properties

Atomic Radius
Molar Volume
Covalent Radius
165 pm
Metallic Radius
Ionic Radius
111.6 pm
Crystal Radius
125.6 pm
Van der Waals Radius
245 pm
Density
8.84 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy
Heat of Vaporization
Heat of Fusion
Heat of Formation
133 kJ/mol
Electrons
Electron Shells2, 8, 18, 32, 29, 8, 2
Valence Electrons4
Electron Configuration[Rn] 5f11 7s2
Oxidation States2, 3, 4
Electronegativity
Electrophilicity
Phases
PhaseSolid
Gas Phase
Boiling Point
Melting Point
1,133.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color
Colorless
Appearancesilver-colored
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
Crystal Structure ()
Lattice Constant
Lattice Angles
Mechanical Properties
Hardness
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound
Classification
CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number43
Mendeleev Number34
Pettifor Number38
Geochemical Class
Goldschmidt Classsynthetic
Other
Gas Basicity
Dipole Polarizability
118 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
160
Neutron Mass Absorption
Quantum Numbers5I15/2
Space Group ()

Isotopes of Einsteinium

Stable Isotopes0
Unstable Isotopes20
Radioactive Isotopes20

239Es

AbundanceRadioactive ☢️
Relative Atomic Mass
239.06831 ± 0.000322 Da
Mass Number239
G-Factor
Half Life
Spin3/2
Quadrupole Moment
Discovery Year
Parity-

239Es Decay Modes
Decay ModeIntensity
α (α emission)%
β+ (β+ decay; β+ = ϵ + e+)%
SF (spontaneous fission)%

240Es

AbundanceRadioactive ☢️
Relative Atomic Mass
240.068949 ± 0.000393 Da
Mass Number240
G-Factor
Half Life
6 ± 1.7 s
Spin4
Quadrupole Moment
Discovery Year2017
Parity-

240Es Decay Modes
Decay ModeIntensity
α (α emission)70%
β+ (β+ decay; β+ = ϵ + e+)30%
β+ SF (β+-delayed fission)0.16%

241Es

AbundanceRadioactive ☢️
Relative Atomic Mass
241.068592 ± 0.000248 Da
Mass Number241
G-Factor
Half Life
5.1 ± 0.8 s
Spin3/2
Quadrupole Moment
Discovery Year1996
Parity-

241Es Decay Modes
Decay ModeIntensity
α (α emission)100%
β+ (β+ decay; β+ = ϵ + e+)%

242Es

AbundanceRadioactive ☢️
Relative Atomic Mass
242.069567 ± 0.000276 Da
Mass Number242
G-Factor
Half Life
17.8 ± 1.6 s
Spin2
Quadrupole Moment
Discovery Year1994
Parity+

242Es Decay Modes
Decay ModeIntensity
α (α emission)57%
β+ (β+ decay; β+ = ϵ + e+)43%
β+ SF (β+-delayed fission)0.6%

243Es

AbundanceRadioactive ☢️
Relative Atomic Mass
243.069508 ± 0.000222 Da
Mass Number243
G-Factor
Half Life
22.1 ± 1.4 s
Spin7/2
Quadrupole Moment
Discovery Year1973
Parity+

243Es Decay Modes
Decay ModeIntensity
α (α emission)61%
β+ (β+ decay; β+ = ϵ + e+)%
SF (spontaneous fission)1%

244Es

AbundanceRadioactive ☢️
Relative Atomic Mass
244.070881 ± 0.000195 Da
Mass Number244
G-Factor
Half Life
37 ± 4 s
Spin6
Quadrupole Moment
Discovery Year1973
Parity+

244Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)95%
α (α emission)5%
β+ SF (β+-delayed fission)0.011%

245Es

AbundanceRadioactive ☢️
Relative Atomic Mass
245.071192 ± 0.000178 Da
Mass Number245
G-Factor
Half Life
1.11 ± 0.06 m
Spin3/2
Quadrupole Moment
Discovery Year1967
Parity-

245Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)51%
α (α emission)49%

246Es

AbundanceRadioactive ☢️
Relative Atomic Mass
246.072806474 ± 0.000096538 Da
Mass Number246
G-Factor
Half Life
7.5 ± 0.5 m
Spin4
Quadrupole Moment
Discovery Year1954
Parity-

246Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)90.1%
α (α emission)9.9%
β+ SF (β+-delayed fission)0.003%

247Es

AbundanceRadioactive ☢️
Relative Atomic Mass
247.073621929 ± 0.00002087 Da
Mass Number247
G-Factor
Half Life
4.55 ± 0.26 m
Spin7/2
Quadrupole Moment
Discovery Year1967
Parity+

247Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)93%
α (α emission)7%
SF (spontaneous fission)%

248Es

AbundanceRadioactive ☢️
Relative Atomic Mass
248.075469 ± 0.000056 Da
Mass Number248
G-Factor
Half Life
24 ± 3 m
Spin2
Quadrupole Moment
Discovery Year1956
Parity-

248Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)0.25%
β+ SF (β+-delayed fission)3.5%

249Es

AbundanceRadioactive ☢️
Relative Atomic Mass
249.076409 ± 0.000032 Da
Mass Number249
G-Factor
Half Life
102.2 ± 0.6 m
Spin7/2
Quadrupole Moment
Discovery Year1956
Parity+

249Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)0.57%

250Es

AbundanceRadioactive ☢️
Relative Atomic Mass
250.078611 ± 0.000107 Da
Mass Number250
G-Factor
Half Life
8.6 ± 0.1 h
Spin6
Quadrupole Moment
Discovery Year1956
Parity

250Es Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)%

251Es

AbundanceRadioactive ☢️
Relative Atomic Mass
251.079991431 ± 0.000005676 Da
Mass Number251
G-Factor
Half Life
33 ± 1 h
Spin3/2
Quadrupole Moment
Discovery Year1956
Parity-

251Es Decay Modes
Decay ModeIntensity
ϵ (electron capture)99.5%
α (α emission)0.5%

252Es

AbundanceRadioactive ☢️
Relative Atomic Mass
252.082979173 ± 0.000053736 Da
Mass Number252
G-Factor
Half Life
471.7 ± 1.9 d
Spin4
Quadrupole Moment
Discovery Year1956
Parity+

252Es Decay Modes
Decay ModeIntensity
α (α emission)78%
ϵ (electron capture)22%

253Es

AbundanceRadioactive ☢️
Relative Atomic Mass
253.084821241 ± 0.000001341 Da
Mass Number253
G-Factor
1.1714285714286 ± 0.02
Half Life
20.47 ± 0.03 d
Spin7/2
Quadrupole Moment
6.7 ± 0.8
Discovery Year1954
Parity+

253Es Decay Modes
Decay ModeIntensity
α (α emission)100%
SF (spontaneous fission)8.7%

254Es

AbundanceRadioactive ☢️
Relative Atomic Mass
254.088024337 ± 0.000003152 Da
Mass Number254
G-Factor
Half Life
275.7 ± 0.5 d
Spin7
Quadrupole Moment
Discovery Year1954
Parity+

254Es Decay Modes
Decay ModeIntensity
α (α emission)100%
ϵ (electron capture)%
β (β decay)1.74%
SF (spontaneous fission)3%

255Es

AbundanceRadioactive ☢️
Relative Atomic Mass
255.090273504 ± 0.000011612 Da
Mass Number255
G-Factor
Half Life
39.8 ± 1.2 d
Spin7/2
Quadrupole Moment
Discovery Year1954
Parity+

255Es Decay Modes
Decay ModeIntensity
β (β decay)92%
α (α emission)8%
SF (spontaneous fission)0.0041%

256Es

AbundanceRadioactive ☢️
Relative Atomic Mass
256.093597 ± 0.000107 Da
Mass Number256
G-Factor
Half Life
7.6 h
Spin7
Quadrupole Moment
Discovery Year1976
Parity+

256Es Decay Modes
Decay ModeIntensity
β (β decay)100%
β SF (β-delayed fission)0.002%

257Es

AbundanceRadioactive ☢️
Relative Atomic Mass
257.095979 ± 0.000441 Da
Mass Number257
G-Factor
Half Life
7.7 ± 0.2 d
Spin7/2
Quadrupole Moment
Discovery Year1987
Parity+

257Es Decay Modes
Decay ModeIntensity
β (β decay)100%
α (α emission)%

258Es

AbundanceRadioactive ☢️
Relative Atomic Mass
258.09952 ± 0.00043 Da
Mass Number258
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

258Es Decay Modes
Decay ModeIntensity
β (β decay)%
α (α emission)%

History

Einsteinium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952. It was identified by Albert Ghiorso and co-workers at the University of California, Berkeley in collaboration with the Argonne and Los Alamos National Laboratories, in the fallout from the Ivy Mike nuclear test. The new element was produced by the nuclear explosion in miniscule amounts by the addition of 15 neutrons to uranium-238. Named after Albert Einstein

DiscoverersArgonne, Los Alamos, U of Calif
Discovery LocationUnited States
Discovery Year1952
Etymology (Name Origin)Named in honor of the scientist Albert Einstein.
Pronunciationine-STINE-i-em (English)
Einsteinium is harmful due to its radioactivity
Einsteinium is the first divalent metal in the actinide series

Uses

Einsteinium is mainly used for scientific research purposes. The rare isotope einsteinium-254 is favored for production of ultraheavy elements. Einsteinium-254 was used as the calibration marker in the chemical analysis spectrometer of the Surveyor 5 lunar probe. It has no significant commercial applications.

Sources

Made by bombarding uranium with neutrons.

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

Nuclear Screening Constants