72 · Hf
Hafnium
Urbain’s celtium is not upheld. Coster and Hevesy identify hafnium in 1923.
Identity
- Atomic number
- 72
- Symbol
- Hf
- Canonical name
- Hafnium
- Category
- transition metal
- Group
- 4
- Period
- 6
- Block
- d
- Former names
- celtium
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
- 178.492 u
- Electron configuration
- [Xe] 4f14 5d2 6s2
- Electrons per shell
- 2, 8, 18, 32, 10, 2
- Standard state
- solid
- Density
- 13.31 g/cm³
- Melting point
- 2,506 K
- Boiling point
- 4,876 K
- Electronegativity
- 1.3 Pauling
- First ionization energy
- 658.5 kJ/mol
- Electron affinity
- 17.18 kJ/mol
History
Celtium
Discovery · rejected · 1911
Urbain announces celtium as element 72. This identification is not upheld.
Hafnium in Copenhagen
Discovery · confirmed · 1923
Coster and Hevesy identify hafnium by X-ray spectroscopy in zircons.
Etymology
- Theme
- place
- Language
- latin
- Root
- Hafnia
- Meaning
- Copenhagen, Hafnia
Scientists
Places and institutions
- Paris — historical setting : France — present country : France
- Copenhagen — historical setting : Denmark — present country : Denmark
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.
- John Emsley, Nature’s Building Blocks: An A–Z Guide to the Elements