Dubnium

Dubnium (Db)

Also known as Hahnium, Ha. Radioactive transactinide element. Half-life of 1.6s. Discovered in 1970 by Berkeley researchers. So far, seven isotopes have been discovered.
Atomic Number105
Atomic Weight268
Mass Number255
Group5
Period7
Blockd
Protons105 p+
Neutrons150 n0
Electrons105 e-
Electron shell 105 Dubnium.svg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
Atomic Volume
Covalent Radius
149 pm
Metallic Radius
Ionic Radius
Crystal Radius
Van der Waals radius
Density
29.3 g/cm³
Boiling Point
Melting Point
Electrons per shell2, 8, 18, 32, 32, 11, 2
Electronegativity
Electrophilicity
Proton Affinity
Electron Affinity
Ionization Potential
Heat of Vaporization
Heat of Fusion
Heat of Formation
Molar Heat Capacity
Specific Heat Capacity
Thermal Conductivity
Gas Basicity
Dipole Polarizability
42 a₀
C6 Dispersion Coefficient
Oxidation States5
Color
Colorless
Crystal Structure ()
Lattice Constant
Bulk Modulus
Electrical Resistivity
Electron Configuration[Rn] 5f14 6d3 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
CategoryTransition metals, Transition metals
CAS GroupVA
IUPAC GroupVB
Glawe Number
Mendeleev Number50
Pettifor Number
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 Dubnium

Stable Isotopes
Unstable Isotopes
255Db 256Db 257Db 258Db 259Db 260Db 261Db 262Db 263Db 264Db 265Db 266Db 267Db 268Db 269Db 270Db

History

Dubnium was reportedly first discovered in 1968 at the Joint Institute for Nuclear Research at Dubna. Researchers there bombarded an americium-243 target with neon-22 ions. In the same year, a team led by Albert Ghiorso working at the University of California, Berkeley conclusively synthesized the element by bombarding a californium-249 target with nitrogen-15 ions. Named after the Russian town of Dubna

DiscoverersA. Ghiorso, et al
Discovery LocationUnited States
Discovery Year1970
Name OriginNamed after the city of Dubna, the site of the JINR.
Dubnium is harmful due to its radioactivity
The Berkeley team proposed the name hahnium for the element

Uses

Dubnium is used for scientific research purposes only. It has no significant commercial applications.

Sources

Made by bombarding californium-249 with a beam of nitrogen-15