Element 97
Berkelium (Bk)
Berkelium (Bk) is element 97 of the periodic table, a actinide in period 7 (f-block) with an atomic mass of 247 and is a solid at standard conditions.
At a glance
- Atomic number
- 97
- Symbol
- Bk
- Atomic mass
- 247 u
- Category
- Actinides
- Period
- 7
- Block
- f-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f9 7s2
- Shorthand configuration
- [Rn] 5f9 7s2
- Electrons per shell
- 2, 8, 18, 32, 27, 8, 2
- Oxidation states
- +3, +4
Physical properties
- Melting point
- 1259 K
- Boiling point
- 2900 K
- Density
- 14.79 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.3
- Atomic radius
- 170 pm
- First ionization energy
- 601 kJ/mol
- Electron affinity
- -165 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Bk-247 | 247.07031 | — | Half-life 1380 years |
Common uses
- Scientific research only
Discovery
- Year
- 1949
- Discovered by
- Stanley G. Thompson, Albert Ghiorso, Glenn T. Seaborg
- Country
- USA