Berkelium (Bk)
Actinide · Radioactive · Synthetic
Berkelium is a research-only synthetic element named after Berkeley, California, where a string of transuranium elements were first made. Its main use is as a stepping stone: berkelium targets helped create element 117.
Position on the periodic table
Atomic properties
| Atomic number | 97 |
|---|---|
| Atomic mass | 247 amu |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f9 |
| Noble gas shorthand | [Rn] 5f9 7s2 |
| Electrons per shell | 2, 8, 18, 32, 27, 8, 2 |
| Valence electrons (outer shell) | 2 |
| Common oxidation states | +3, +4 |
| Electronegativity (Pauling) | 1.3 |
| Covalent radius (approx.) | Not available |
| First ionization energy | 601 kJ/mol |
| Electron affinity | -165.2 kJ/mol |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Density | 14.78 g/cm³ |
| Melting point | 985.85 °C (1259 K) |
| Boiling point | 2626.8 °C (2900 K) |
| Appearance | silvery |
| Radioactive | Yes |
| Origin | Synthetic (lab-made) |
Electron configuration of berkelium
Berkelium's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f9, usually shortened to [Rn] 5f9 7s2. Its electrons occupy 7 shells (2, 8, 18, 32, 27, 8, 2), placing it in period 7 of the f-block. Explore it interactively in the electron configuration calculator.
Uses of berkelium
- Research; target material for synthesising superheavy elements
Biological role: None.
Occurrence: Entirely synthetic.
Common compounds of berkelium
BkO2
Berkelium dioxide
History and discovery
Discovered: 1949 — Lawrence Berkeley National Laboratory. Name origin: Named after Berkeley, California, echoing terbium's tribute to Ytterby.
Thompson, Ghiorso and Seaborg synthesised berkelium in 1949 by bombarding americium with alpha particles.
Safety notes
Radiotoxic; produced in microgram-to-milligram amounts only.
Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.
Practice questions
Quick practice: Berkelium
1. What is the chemical symbol of Berkelium?
2. What is the atomic number of Berkelium?
3. Which category does Berkelium belong to?
4. What is the state of Berkelium at room temperature?
5. Which period of the periodic table is Berkelium in?
Berkelium FAQs
What is the atomic number of berkelium?
Berkelium's atomic number is 97 — every berkelium atom has 97 protons in its nucleus.
What is the symbol for berkelium?
Bk. Named after Berkeley, California, echoing terbium's tribute to Ytterby.
Is berkelium a metal, nonmetal, or metalloid?
Berkelium is classified as a actinide.
What state is berkelium at room temperature?
At about 25 °C, berkelium is a solid. It melts at 985.85 °C.
What is berkelium used for?
Key uses include: research; target material for synthesising superheavy elements.
Related elements
Keep working with this element
Spotted an error? Report a correction · Data sources