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 Number240
Group
Period7
Blockf
Protons99 p+
Neutrons141 n0
Electrons99 e-
Einsteinium.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
Atomic Volume
Covalent Radius
165 pm
Metallic Radius
Ionic Radius
111.6 pm
Crystal Radius
125.6 pm
Van der Waals radius
245.00000000000003 pm
Density
8.84 g/cm³
Boiling Point
1,130 K
Melting Point
Electrons per shell2, 8, 18, 32, 29, 8, 2
Electronegativity
Electrophilicity
Proton Affinity
Electron Affinity
Ionization Potential
Heat of Vaporization
Heat of Fusion
Heat of Formation
133 kJ/mol
Molar Heat Capacity
Specific Heat Capacity
Thermal Conductivity
Gas Basicity
Dipole Polarizability
118 a₀
C6 Dispersion Coefficient
Oxidation States2, 3
Color
Colorless
Crystal Structure ()
Lattice Constant
Bulk Modulus
Electrical Resistivity
Electron Configuration[Rn] 5f11 7s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryActinides, Actinides
CAS Group
IUPAC Group
Glawe Number43
Mendeleev Number34
Pettifor Number38
Geochemical Class
Goldschmidt Classsynthetic
Radioactivity
RadioactiveYes ☢️
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universena

Isotopes of Einsteinium

Stable Isotopes
Unstable Isotopes
240Es 241Es 242Es 243Es 244Es 245Es 246Es 247Es 248Es 249Es 250Es 251Es 252Es 253Es 254Es 255Es 256Es 257Es 258Es

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
Name OriginNamed in honor of the scientist Albert Einstein.
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.