Quick answerRadon (Rn) is a noble gas with atomic number 86 and a mass number of 222 (the most stable isotope), in group 18, period 6. It was discovered by Friedrich Ernst Dorn in 1900. It is used for cancer treatment research and geological tracing. Its electron configuration is [Xe] 4f14 5d10 6s2 6p6.
Radon is an invisible radioactive gas that seeps from rocks into homes, where it is the second-biggest cause of lung cancer.
Key facts
| Symbol | Rn |
|---|---|
| Atomic number | 86 |
| Atomic mass | [222] — mass number of the most stable isotope |
| Category | noble gas |
| Group | 18 |
| Period | 6 |
| Block | p-block |
| Electron configuration | [Xe] 4f14 5d10 6s2 6p6 |
| Discovered | Friedrich Ernst Dorn, 1900 |
| Uses | cancer treatment research, geological tracing, leak detection, radiotherapy |
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Helium (He) — another noble gas, atomic number 2
- Neon (Ne) — another noble gas, atomic number 10
- Argon (Ar) — another noble gas, atomic number 18
- Krypton (Kr) — another noble gas, atomic number 36
- Xenon (Xe) — another noble gas, atomic number 54
- Oganesson (Og) — another noble gas, atomic number 118
Sources & last updated
- CIAAW — Standard Atomic Weights
- PubChem Periodic Table
- Wikipedia — Timeline of chemical element discoveries
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.