95 · Am
Americium
Produced in 1944 by Seaborg’s team.
Identity
- Atomic number
- 95
- Symbol
- Am
- Canonical name
- Americium
- Category
- actinide
- Group
- unassigned
- Period
- 7
- Block
- f
Series set apart from the main table. Whether group 3 is lanthanum or lutetium (actinium or lawrencium) is still discussed, so the group is left empty.
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
- [243] No standard atomic weight. The number shown is the conventional mass number used in tables, not a measured mass in u.
- Electron configuration
- [Rn] 5f7 7s2
- Electrons per shell
- 2, 8, 18, 32, 25, 8, 2
- Standard state
- solid
- Density
- 12 g/cm³
- Melting point
- 1,449 K
- Boiling point
- 2,880 K
- Electronegativity
- 1.13 Pauling
- First ionization energy
- 578 kJ/mol
- Electron affinity
- 9.93 kJ/mol
Notable isotopes
This summary is not an inventory of every isotope.
Conventional mass number: 243
History
Americium
Synthesis · confirmed · 1944
Seaborg, James, Morgan, and Ghiorso produce americium by successive irradiations of plutonium.
Etymology
- Theme
- continent
- Language
- latin
- Root
- America
- Meaning
- America
Scientists
Places and institutions
- Chicago — 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)