Berkelium

Symbol: Bk
Atomic number: 97
Category: actinides
Group: n/a
Period: 7
Block: f
Atomic weight: (247) g/mol
Electrons per shell: 2, 8, 18, 32, 27, 8, 2
CAS number: 7440-40-6
Phase: solid
Density: 14.78 kg/dm³ (alpha) (near room temperature) 13.25 kg/dm³ (beta) (near room temperature)
Melting point: (beta) 1259 K (986 °C, 1807 °F)
Boiling point: unknown
Crystal structure: hexagonal close-packed
Oxidation states: 3, 4
Electronegativity: 1.3 (Pauling scale)
Name's origin: Berkeley
Name's meaning: a research group in University of California, Berkeley discovered the element
Facts:
- a radioactive metal
- was first synthesized by bombarding americium with alpha particles (helium ions)
- was the fifth transuranic element to be synthesized
- is a silvery metal that would easily oxidize in air at elevated temperatures and would be soluble in dilute mineral acids
- 19 radioisotopes of berkelium have been characterized, with the most stable being berkelium-247 with a half-life of 1380 years
- like other actinides, berkelium bio-accumulates in skeletal tissue
- has no known uses outside of basic research
- plays no biological role