Einsteinium (Es)

Einsteinium is the 99th element in the periodic table and has a symbol of Es and atomic number of 99. It has an atomic weight of (252) and a mass number of 239. Einsteinium has ninety-nine protons and one hundred forty neutrons in its nucleus, and ninety-nine electrons in seven shells. It is located in group zero, period seven and block f of the periodic table. 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 Number	99
Atomic Weight	252
Mass Number	239

Group
Period	7
Block	f

Protons	99 p⁺
Neutrons	140 n⁰
Electrons	99 e^-

Properties

Physical Properties
Atomic Radius
Molar Volume
Covalent Radius	165 pm 140 pm
Metallic Radius
Ionic Radius	111.6 pm
Crystal Radius	125.6 pm
Van der Waals Radius	245 pm 329.9 pm
Density	8.84 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy	6.3676 eV/particle 12.2 eV/particle 22.7 eV/particle 38.8 eV/particle 54.1 eV/particle 71 eV/particle 97 eV/particle 112.9 eV/particle 137 eV/particle 157 eV/particle 180 eV/particle 206 eV/particle 231 eV/particle 252 eV/particle 270 eV/particle 294 eV/particle 317 eV/particle 342 eV/particle 367 eV/particle 398 eV/particle 421 eV/particle 576 eV/particle 606 eV/particle 638 eV/particle 672 eV/particle 705 eV/particle 738 eV/particle 790 eV/particle 824 eV/particle 861 eV/particle 895 eV/particle 1,060 eV/particle 1,100 eV/particle 1,140 eV/particle 1,180 eV/particle 1,310 eV/particle 1,360 eV/particle 1,480 eV/particle 1,530 eV/particle 1,690 eV/particle 1,780 eV/particle 1,870 eV/particle 1,950 eV/particle 2,040 eV/particle 2,130 eV/particle 2,220 eV/particle 2,300 eV/particle 2,410 eV/particle 2,490 eV/particle 2,580 eV/particle 2,680 eV/particle 2,760 eV/particle 2,900 eV/particle 3,294 eV/particle 3,370 eV/particle 3,449 eV/particle 3,535 eV/particle 3,616 eV/particle 3,694 eV/particle 3,866 eV/particle 3,947 eV/particle 4,038 eV/particle 4,120 eV/particle 4,456 eV/particle 4,537 eV/particle 4,620 eV/particle 4,700 eV/particle 5,260 eV/particle 5,350 eV/particle 5,600 eV/particle 5,690 eV/particle 8,960 eV/particle 9,140 eV/particle 9,330 eV/particle 9,530 eV/particle 9,720 eV/particle 9,910 eV/particle 10,400 eV/particle 10,590 eV/particle 10,810 eV/particle 11,010 eV/particle 11,570 eV/particle 11,740 eV/particle 11,930 eV/particle 12,110 eV/particle 13,810 eV/particle 14,030 eV/particle 14,460 eV/particle 14,700 eV/particle 29,700 eV/particle 30,100 eV/particle 30,700 eV/particle 31,100 eV/particle 37,400 eV/particle 38,100 eV/particle 38,900 eV/particle 39,451.4 eV/particle 154,328 eV/particle 156,926 eV/particle

Heat of Vaporization
Heat of Fusion
Heat of Formation	133 kJ/mol
Electrons
Electron Shells	2, 8, 18, 32, 29, 8, 2

Valence Electrons	2

Electron Configuration	[Rn] 5f¹¹ 7s²

Oxidation States	2, 3, 4
Electronegativity	0.21427
Electrophilicity
Phases
Phase	Solid
Gas Phase
Boiling Point
Melting Point	1,133.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Einsteinium is a Colorless. Es has a CPK of #ffffff, Jmol of #b31fd4, and MOLCAS GV of #b31fd4. The Appearance of Element 99 is silver-colored.
Color	Colorless #ffffff #b31fd4 #b31fd4
Appearance	silver-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
The lattice angles of Einsteinium is .
Crystal Structure	()
Lattice Constant
Lattice Angles
Mechanical Properties

Hardness
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound
Classification
The Glawe Number of Einsteinium is 43. The Mendeleev Number of Es is 34. The Pettifor Number of Element 99 is 38. The Goldschmidt Class of Einsteinium (Es) is synthetic.
Category	Actinides, Actinides
CAS Group
IUPAC Group
Glawe Number	43
Mendeleev Number	34
Pettifor Number	38
Geochemical Class
Goldschmidt Class	synthetic
Other
The Dipole Polarizability of Einsteinium is 118 plus or minus 20 a₀. The Allotropes of Es is . The Neutron Cross Section of Element 99 is 160. The Quantum Numbers of Einsteinium (Es) is 5I15/2. The Space Group of Einsteinium is ().
Gas Basicity
Dipole Polarizability	118 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section	160
Neutron Mass Absorption
Quantum Numbers	5I15/2
Space Group	()

Isotopes of Einsteinium

Stable Isotopes	0
Unstable Isotopes	20
Radioactive Isotopes	20

²³⁹Es

Abundance	Radioactive ☢️
Relative Atomic Mass	239.06831 ± 0.000322 Da
Mass Number	239
G-Factor
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year
Parity	-

²³⁹Es Decay Modes

Decay Mode	Intensity
α (α emission)	%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
SF (spontaneous fission)	%

²⁴⁰Es

Abundance	Radioactive ☢️
Relative Atomic Mass	240.068949 ± 0.000393 Da
Mass Number	240
G-Factor
Half Life	6 ± 1.7 s
Spin	4
Quadrupole Moment
Discovery Year	2017
Parity	-

²⁴⁰Es Decay Modes

Decay Mode	Intensity
α (α emission)	70%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	30%
β⁺ SF (β⁺-delayed fission)	0.16%

²⁴¹Es

Abundance	Radioactive ☢️
Relative Atomic Mass	241.068592 ± 0.000248 Da
Mass Number	241
G-Factor
Half Life	5.1 ± 0.8 s
Spin	3/2
Quadrupole Moment
Discovery Year	1996
Parity	-

²⁴¹Es Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁴²Es

Abundance	Radioactive ☢️
Relative Atomic Mass	242.069567 ± 0.000276 Da
Mass Number	242
G-Factor
Half Life	17.8 ± 1.6 s
Spin	2
Quadrupole Moment
Discovery Year	1994
Parity	+

²⁴²Es Decay Modes

Decay Mode	Intensity
α (α emission)	57%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	43%
β⁺ SF (β⁺-delayed fission)	0.6%

²⁴³Es

Abundance	Radioactive ☢️
Relative Atomic Mass	243.069508 ± 0.000222 Da
Mass Number	243
G-Factor
Half Life	22.1 ± 1.4 s
Spin	7/2
Quadrupole Moment
Discovery Year	1973
Parity	+

²⁴³Es Decay Modes

Decay Mode	Intensity
α (α emission)	61%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
SF (spontaneous fission)	1%

²⁴⁴Es

Abundance	Radioactive ☢️
Relative Atomic Mass	244.070881 ± 0.000195 Da
Mass Number	244
G-Factor
Half Life	37 ± 4 s
Spin	6
Quadrupole Moment
Discovery Year	1973
Parity	+

²⁴⁴Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	95%
α (α emission)	5%
β⁺ SF (β⁺-delayed fission)	0.011%

²⁴⁵Es

Abundance	Radioactive ☢️
Relative Atomic Mass	245.071192 ± 0.000178 Da
Mass Number	245
G-Factor
Half Life	1.11 ± 0.06 m
Spin	3/2
Quadrupole Moment
Discovery Year	1967
Parity	-

²⁴⁵Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	51%
α (α emission)	49%

²⁴⁶Es

Abundance	Radioactive ☢️
Relative Atomic Mass	246.072806474 ± 0.000096538 Da
Mass Number	246
G-Factor
Half Life	7.5 ± 0.5 m
Spin	4
Quadrupole Moment
Discovery Year	1954
Parity	-

²⁴⁶Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	90.1%
α (α emission)	9.9%
β⁺ SF (β⁺-delayed fission)	0.003%

²⁴⁷Es

Abundance	Radioactive ☢️
Relative Atomic Mass	247.073621929 ± 0.00002087 Da
Mass Number	247
G-Factor
Half Life	4.55 ± 0.26 m
Spin	7/2
Quadrupole Moment
Discovery Year	1967
Parity	+

²⁴⁷Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	93%
α (α emission)	7%
SF (spontaneous fission)	%

²⁴⁸Es

Abundance	Radioactive ☢️
Relative Atomic Mass	248.075469 ± 0.000056 Da
Mass Number	248
G-Factor
Half Life	24 ± 3 m
Spin	2
Quadrupole Moment
Discovery Year	1956
Parity	-

²⁴⁸Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.25%
β⁺ SF (β⁺-delayed fission)	3.5%

²⁴⁹Es

Abundance	Radioactive ☢️
Relative Atomic Mass	249.076409 ± 0.000032 Da
Mass Number	249
G-Factor
Half Life	102.2 ± 0.6 m
Spin	7/2
Quadrupole Moment
Discovery Year	1956
Parity	+

²⁴⁹Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.57%

²⁵⁰Es

Abundance	Radioactive ☢️
Relative Atomic Mass	250.078611 ± 0.000107 Da
Mass Number	250
G-Factor
Half Life	8.6 ± 0.1 h
Spin	6
Quadrupole Moment
Discovery Year	1956
Parity

²⁵⁰Es Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	%

²⁵¹Es

Abundance	Radioactive ☢️
Relative Atomic Mass	251.079991431 ± 0.000005676 Da
Mass Number	251
G-Factor
Half Life	33 ± 1 h
Spin	3/2
Quadrupole Moment
Discovery Year	1956
Parity	-

²⁵¹Es Decay Modes

Decay Mode	Intensity
ϵ (electron capture)	99.5%
α (α emission)	0.5%

²⁵²Es

Abundance	Radioactive ☢️
Relative Atomic Mass	252.082979173 ± 0.000053736 Da
Mass Number	252
G-Factor
Half Life	471.7 ± 1.9 d
Spin	4
Quadrupole Moment
Discovery Year	1956
Parity	+

²⁵²Es Decay Modes

Decay Mode	Intensity
α (α emission)	78%
ϵ (electron capture)	22%

²⁵³Es

Abundance	Radioactive ☢️
Relative Atomic Mass	253.084821241 ± 0.000001341 Da
Mass Number	253
G-Factor	1.1714285714286 ± 0.02
Half Life	20.47 ± 0.03 d
Spin	7/2
Quadrupole Moment	6.7 ± 0.8
Discovery Year	1954
Parity	+

²⁵³Es Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	8.7%

²⁵⁴Es

Abundance	Radioactive ☢️
Relative Atomic Mass	254.088024337 ± 0.000003152 Da
Mass Number	254
G-Factor
Half Life	275.7 ± 0.5 d
Spin	7
Quadrupole Moment
Discovery Year	1954
Parity	+

²⁵⁴Es Decay Modes

Decay Mode	Intensity
α (α emission)	100%
ϵ (electron capture)	%
β⁻ (β⁻ decay)	1.74%
SF (spontaneous fission)	3%

²⁵⁵Es

Abundance	Radioactive ☢️
Relative Atomic Mass	255.090273504 ± 0.000011612 Da
Mass Number	255
G-Factor
Half Life	39.8 ± 1.2 d
Spin	7/2
Quadrupole Moment
Discovery Year	1954
Parity	+

²⁵⁵Es Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	92%
α (α emission)	8%
SF (spontaneous fission)	0.0041%

²⁵⁶Es

Abundance	Radioactive ☢️
Relative Atomic Mass	256.093597 ± 0.000107 Da
Mass Number	256
G-Factor
Half Life	7.6 h
Spin	7
Quadrupole Moment
Discovery Year	1976
Parity	+

²⁵⁶Es Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ SF (β⁻-delayed fission)	0.002%

²⁵⁷Es

Abundance	Radioactive ☢️
Relative Atomic Mass	257.095979 ± 0.000441 Da
Mass Number	257
G-Factor
Half Life	7.7 ± 0.2 d
Spin	7/2
Quadrupole Moment
Discovery Year	1987
Parity	+

²⁵⁷Es Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
α (α emission)	%

²⁵⁸Es

Abundance	Radioactive ☢️
Relative Atomic Mass	258.09952 ± 0.00043 Da
Mass Number	258
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁵⁸Es Decay Modes

Decay Mode	Intensity
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

Discoverers	Argonne, Los Alamos, U of Calif
Discovery Location	United States
Discovery Year	1952
Etymology (Name Origin)	Named in honor of the scientist Albert Einstein.
Pronunciation	ine-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

Einsteinium on ChemicalAid

Australian Educational Vocabulary ID	scot/3516
CAS Registry Number	7429-92-7
ChEBI ID	33393
ChemSpider ID	22356
DSSTOX compound identifier	DTXCID90147796
DSSTox substance ID	DTXSID30225305
Den Store Danske ID	einsteinium
Dizionario delle Scienze Fisiche ID	einsteinio
Elhuyar ZTH ID	022704
Encyclopedia of China ID (Second Edition)	190938
Encyclopædia Britannica Online ID	science/einsteinium
Encyclopædia Universalis ID	einsteinium
Freebase ID	/m/028bh5n
French Vikidia ID	Einsteinium
GND ID	4151415-4
Gran Enciclopèdia Catalana ID	0100433
Great Russian Encyclopedia Online ID	4940532
InChI	InChI=1S/Es
InChIKey	CKBRQZNRCSJHFT-UHFFFAOYSA-N
KBpedia ID	Einsteinium
MeSH descriptor ID	D004540
OmegaWiki Defined Meaning	157713
PubChem CID	23913
Römpp online ID	RD-05-00380
Store norske leksikon ID	einsteinium
Treccani ID	einstenio
UNII	WV8XL34X3O
USGS Thesaurus ID	1445
WordNet 3.1 Synset ID	14661000-n

Einsteinium (Es)

Properties

Isotopes of Einsteinium

239Es

239Es Decay Modes

240Es

240Es Decay Modes

241Es

241Es Decay Modes

242Es

242Es Decay Modes

243Es

243Es Decay Modes

244Es

244Es Decay Modes

245Es

245Es Decay Modes

246Es

246Es Decay Modes

247Es

247Es Decay Modes

248Es

248Es Decay Modes

249Es

249Es Decay Modes

250Es

250Es Decay Modes

251Es

251Es Decay Modes

252Es

252Es Decay Modes

253Es

253Es Decay Modes

254Es

254Es Decay Modes

255Es

255Es Decay Modes

256Es

256Es Decay Modes

257Es

257Es Decay Modes

258Es

258Es Decay Modes