Atomic number 97
Berkelium
Actinide
No photo: here’s why
Berkelium has only ever been made in amounts smaller than a grain of sand, in a handful of labs on Earth. Almost no one has ever seen it.
Quick facts
- Atomic mass
- 247.00
- Group
- –
- Period
- 7
- State (STP)
- solid
- Electronegativity
- 1.30
- Common ox. states
- +3, +4
Properties
[Rn] 5f⁹ 7s²
- Ionization energy
- 601.0 kJ/mol
- Electron affinity
- –
- Melting point
- 1259.00 K (985.9 °C)
- Boiling point
- 2900.00 K (2626.8 °C)
How dangerous is it?
A man made metal so rare that only tiny weighable amounts have ever existed, all of it strongly radioactive.
- RadioactiveImmediate and cumulative
It is a strong alpha emitter and decays quickly, so even a small sample is intensely active and harmful to cells inside the body. (almost never exists outside a research lab in the first place)
Produced and studied only in shielded gloveboxes at a handful of licensed labs.
How it bonds· family overview
Berkelium (Bk) is an actinide. Like the lanthanides it tends toward a +3 oxidation state, but the early actinides (Th–Am) routinely access +4, +5, +6, even +7 because the 5f electrons are easier to ionize. Most actinides are radioactive; their "bonding" in school is read off the periodic table, not measured in lab.
