Rhenium (Re)
Element 75 · transition metal · group 7, period 6
Rhenium is element 75, a transition metal in group 7 and period 6. Its electron configuration is [Xe] 4f14 5d5 6s2. The shells fill 2, 8, 18, 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. It commonly forms ions with a charge of +7, +4.
- 75 protons
- 2/7 valence e−
- +7, +4
- d-block
Properties
| Atomic number | 75 |
|---|---|
| Symbol | Re |
| Standard atomic weight | 186.21 u |
| Group | 7 |
| Period | 6 |
| Block | d-block |
| Category | transition metal |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2 |
| Noble-gas notation | [Xe] 4f14 5d5 6s2 |
| Electrons per shell | 2, 8, 18, 32, 13, 2 |
| Valence electrons | 2 or 7 |
| Common ionic charge | +7, +4 |
| Electronegativity (Pauling) | 1.9 |
| Protons / electrons | 75 / 75 |
Electron configuration of rhenium
Orbitals fill from the lowest energy upward. Writing that out for rhenium gives 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2, which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2 in plain text.
Everything up to Xe is the same as in that noble gas, so it is usually abbreviated to [Xe] 4f14 5d5 6s2. 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 | 5 | 10 |
| 6s | 2 | 2 |
Rhenium ion charge
Rhenium commonly forms ions with a charge of +7, +4.
Common questions
How many valence electrons does rhenium have?
There is no single agreed answer for rhenium. 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 rhenium?
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2, or [Xe] 4f14 5d5 6s2 written from the previous noble gas. Orbitals fill lowest energy first.
What is the charge of rhenium?
Rhenium commonly forms ions with a charge of +7, +4. Transition metals have several accessible oxidation states, which is why more than one charge is listed.
How many protons, electrons and neutrons does rhenium have?
A neutral rhenium atom has 75 protons and 75 electrons. Its standard atomic weight is 186.21, so the most common isotope has about 111 neutrons.
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