Periodic Table

Dubnium

Transition Metal

Quick Facts about Dubnium

Rf
  • solid- state of matter at room temperature
  • Radioactive- no stable isotopes exist
  • 5, 4, 3- common oxidation states in compounds
Sg

Dubnium (Db) is element 105 on the periodic table. Atomic mass of Db: 268.0000 u. Db is in period 7, group 5. Density of Db: 29.30 g/cm³.

Why Dubnium Matters

Dubnium in everyday life and industry

In Your Home

  • No commercial applications
  • Research element only
  • Studies superheavy element chemistry
  • Extremely difficult to produce

In Your Body

✗ Not essential

No biological role possible. Too short-lived for studies. No biological research.

Safety: Dubnium is radioactive

Discovery of Dubnium

Discovered by A. Ghiorso, et al in United States, 1970

Name origin: Named after the city of Dubna, the site of the JINR.

History & Events

1967
Named after Dubna, Russia
1967
Site of Joint Institute for Nuclear Research
1967
Discovery claimed by both Soviet and American teams
1967
Americans called it hahnium; Soviets called it nielsbohrium

About Dubnium

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 Properties of Db

Atomic Number of Db
105
Atomic Mass of Db
268.0000 u
Electron Configuration
[Rn] 5f14 6d3 7s2
Electronegativity
Block
d-block
Group
5
Period
7

Physical Properties of Db

Phase (STP)
solid
Melting Point of Db
Boiling Point of Db
Density of Db
29.3000 g/cm3

Atomic Radii

Covalent
149 pm

Common Misconceptions

Wrong:Dubnium is named after a scientist.
Correct:Dubnium honors the city of Dubna, Russia, home of the Joint Institute for Nuclear Research (JINR).
Wrong:The name 'dubnium' was used from the start.
Correct:Americans called it 'hahnium' for decades; the Soviet 'dubnium' wasn't adopted by IUPAC until 1997.
Wrong:Dubnium's chemistry has been thoroughly studied.
Correct:Chemical studies are extremely difficult due to short half-lives (seconds) and tiny production quantities.

Isotopes of Dubnium

Dubnium has 0 naturally occurring isotopes, plus 1 notable radioactive isotope.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
268105Db (Db-268)Dubnium-268 isotope268.12567

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Uses

It has no significant commercial applications.

Sources

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

Geochemistry

Goldschmidt
synthetic

Test Your Knowledge

Loading quiz...