104 · Rf
Rutherfordium
Claims from Dubna in 1964 and Berkeley in 1969. Shared credit and the name rutherfordium in 1997.
Identity
- Atomic number
- 104
- Symbol
- Rf
- Canonical name
- Rutherfordium
- Category
- transition metal
- Group
- 4
- Period
- 7
- Block
- d
Bulk chemistry is not established. The table column is not a confirmed family.
Properties
These quantities come from the Periodic Table JSON compilation. They have not yet been checked, one by one, against CIAAW atomic weights or NIST measurements. A value marked estimated is not a measurement.
- Atomic mass
- [267] No standard atomic weight. The number shown is the conventional mass number used in tables, not a measured mass in u.
- Electron configuration
- [Rn] 5f14 6d2 7s2
- Electrons per shell
- 2, 8, 18, 32, 32, 10, 2
- Standard state
- not established
- Density
- 23.2 g/cm³ (estimated) Predicted value: the element has not been observed in bulk.
- Melting point
- 2,400 K (estimated) Predicted value: the element has not been observed in bulk.
- Boiling point
- 5,800 K (estimated) Predicted value: the element has not been observed in bulk.
- First ionization energy
- 580 kJ/mol (estimated)
Notable isotopes
This summary is not an inventory of every isotope.
Conventional mass number: 267
History
Dubna claim
Synthesis · jointly credited · 1964
Dubna announces element 104. Berkeley disputes the evidence. IUPAC later reaches a shared credit, without turning 1964 into an exclusive certainty.
- Target
- 242Pu
- Projectile
- 22Ne
Berkeley claim
Synthesis · jointly credited · 1969
Berkeley announces an independent synthesis. The name rutherfordium is adopted in 1997 inside this dispute.
- Target
- 249Cf
- Projectile
- 12C
The name rutherfordium
Official recognition · officially recognized · 1997
IUPAC adopts the name rutherfordium and a shared credit between Dubna and Berkeley.
Etymology
- Theme
- scientist
- Language
- anglais
- Root
- Rutherford
- Meaning
- Ernest Rutherford
- Temporary systematic name
- unnilquadium (Unq)
- Official adoption
- 1997
Scientists
Places and institutions
- Joint Institute for Nuclear Research
- Berkeley Radiation Laboratory, later Lawrence Berkeley National Laboratory
- Dubna — historical setting : Soviet Union — present country : Russia
- Berkeley — historical setting : United States — present country : United States
See also
Sources
- IUPAC, Periodic Table of the Elements
- Bowserinator, Periodic Table JSON. Compilation secondaire d’où viennent les grandeurs physiques importées (masse, densité, températures, énergies). Elles ne sont pas revérifiées une à une auprès du NIST ou de la CIAAW.
- IUPAC, décisions sur la priorité et les noms des éléments transfermiens (1997–2016)