Berkelium (Bk)
Element 97 · actinide · group 3, period 7
Berkelium is element 97, a actinide in group 3 and period 7. Its electron configuration is [Rn] 5f9 7s2. The shells fill 2, 8, 18, 32, 27, 8, 2. The f-block elements draw on three subshells, so a single valence count is not meaningful for them. It commonly forms ions with a charge of +3.
- 97 protons
- 2/2 valence e−
- +3
- f-block
Properties
| Atomic number | 97 |
|---|---|
| Symbol | Bk |
| Standard atomic weight | 247 u |
| Group | 3 |
| Period | 7 |
| Block | f-block |
| Category | actinide |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f9 6s2 6p6 7s2 |
| Noble-gas notation | [Rn] 5f9 7s2 |
| Electrons per shell | 2, 8, 18, 32, 27, 8, 2 |
| Valence electrons | 2 or 2 |
| Common ionic charge | +3 |
| Electronegativity (Pauling) | 1.3 |
| Protons / electrons | 97 / 97 |
Electron configuration of berkelium
Orbitals fill from the lowest energy upward. Writing that out for berkelium gives 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f9 6s2 6p6 7s2, which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f9 6s2 6p6 7s2 in plain text.
Everything up to Rn is the same as in that noble gas, so it is usually abbreviated to [Rn] 5f9 7s2. The part outside the bracket is what does the chemistry.
| Subshell | Electrons | Capacity |
|---|---|---|
| 1s | 2 | 2 |
| 2s | 2 | 2 |
| 2p | 6 | 6 |
| 3s | 2 | 2 |
| 3p | 6 | 6 |
| 3d | 10 | 10 |
| 4s | 2 | 2 |
| 4p | 6 | 6 |
| 4d | 10 | 10 |
| 4f | 14 | 14 |
| 5s | 2 | 2 |
| 5p | 6 | 6 |
| 5d | 10 | 10 |
| 5f | 9 | 14 |
| 6s | 2 | 2 |
| 6p | 6 | 6 |
| 7s | 2 | 2 |
Berkelium ion charge
Berkelium commonly forms ions with a charge of +3.
Common questions
How many valence electrons does berkelium have?
There is no single agreed answer for berkelium. The f-block elements draw on three subshells, so a single valence count is not meaningful for them. Check which convention your course uses before answering.
What is the electron configuration of berkelium?
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f9 6s2 6p6 7s2, or [Rn] 5f9 7s2 written from the previous noble gas. Orbitals fill lowest energy first.
What is the charge of berkelium?
Berkelium commonly forms ions with a charge of +3. Transition metals have several accessible oxidation states, which is why more than one charge is listed.
How many protons, electrons and neutrons does berkelium have?
A neutral berkelium atom has 97 protons and 97 electrons. Its standard atomic weight is 247, so the most common isotope has about 150 neutrons.
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