Bohrium (Bh)
Element 107 · transition metal · group 7, period 7
Bohrium is element 107, a transition metal in group 7 and period 7. Its electron configuration is [Rn] 5f14 6d5 7s2. The shells fill 2, 8, 18, 32, 32, 13, 2. Courses differ here. Counting only the outer s subshell gives 2; counting the inner d subshell with it gives 7, which is the group number. Its outer shell is already full, so it does not normally form ions at all.
- 107 protons
- 2/7 valence e−
- d-block
Properties
| Atomic number | 107 |
|---|---|
| Symbol | Bh |
| Standard atomic weight | 270 u |
| Group | 7 |
| Period | 7 |
| Block | d-block |
| Category | transition metal |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d5 7s2 |
| Noble-gas notation | [Rn] 5f14 6d5 7s2 |
| Electrons per shell | 2, 8, 18, 32, 32, 13, 2 |
| Valence electrons | 2 or 7 |
| Common ionic charge | none |
| Electronegativity (Pauling) | no accepted value |
| Protons / electrons | 107 / 107 |
Electron configuration of bohrium
Orbitals fill from the lowest energy upward. Writing that out for bohrium gives 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d5 7s2, which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d5 7s2 in plain text.
Everything up to Rn is the same as in that noble gas, so it is usually abbreviated to [Rn] 5f14 6d5 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 | 14 | 14 |
| 6s | 2 | 2 |
| 6p | 6 | 6 |
| 6d | 5 | 10 |
| 7s | 2 | 2 |
Bohrium ion charge
Bohrium does not normally form ions. Its outer shell is already full, so there is nothing to gain by losing or gaining an electron.
Common questions
How many valence electrons does bohrium have?
There is no single agreed answer for bohrium. Courses differ here. Counting only the outer s subshell gives 2; counting the inner d subshell with it gives 7, which is the group number. Check which convention your course uses before answering.
What is the electron configuration of bohrium?
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d5 7s2, or [Rn] 5f14 6d5 7s2 written from the previous noble gas. Orbitals fill lowest energy first.
How many protons, electrons and neutrons does bohrium have?
A neutral bohrium atom has 107 protons and 107 electrons. Its standard atomic weight is 270, so the most common isotope has about 163 neutrons.
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