Radon (Rn)
Element 86 · noble gas · group 18, period 6
Radon is element 86, a noble gas in group 18 and period 6. Its electron configuration is [Xe] 4f14 5d10 6s2 6p6. That leaves 8 valence electrons in the outer shell, with the shells filling 2, 8, 18, 32, 18, 8. Its outer shell is already full, so it does not normally form ions at all.
- 86 protons
- 8 valence e−
- p-block
Properties
| Atomic number | 86 |
|---|---|
| Symbol | Rn |
| Standard atomic weight | 222 u |
| Group | 18 |
| Period | 6 |
| Block | p-block |
| Category | noble gas |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 |
| Noble-gas notation | [Xe] 4f14 5d10 6s2 6p6 |
| Electrons per shell | 2, 8, 18, 32, 18, 8 |
| Valence electrons | 8 |
| Common ionic charge | none |
| Electronegativity (Pauling) | 2.2 |
| Protons / electrons | 86 / 86 |
Electron configuration of radon
Orbitals fill from the lowest energy upward. Writing that out for radon gives 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6, which is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 in plain text.
Everything up to Xe is the same as in that noble gas, so it is usually abbreviated to [Xe] 4f14 5d10 6s2 6p6. 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 |
| 6s | 2 | 2 |
| 6p | 6 | 6 |
Radon ion charge
Radon 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 radon have?
Radon has 8 valence electrons. For a main-group element the count is the group number minus 10, and radon is in group 18.
What is the electron configuration of radon?
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6, or [Xe] 4f14 5d10 6s2 6p6 written from the previous noble gas. Orbitals fill lowest energy first.
How many protons, electrons and neutrons does radon have?
A neutral radon atom has 86 protons and 86 electrons. Its standard atomic weight is 222, so the most common isotope has about 136 neutrons.
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