Radon (Rn)

General Information

• Symbol: Rn
• Atomic Number: 86
• Atomic Weight: [222] u (varies due to multiple isotopes)
• Element Category: Noble gas
• Group: 18
• Period: 6
• Block: p-block

Physical Properties

• Appearance: Colorless gas under normal conditions; glows yellow to orange-red when cooled to below its freezing point
• Density: 9.73 g/L (gas at 0 °C, 101.3 kPa)
• Melting Point: -71 °C (-96 °F)
• Boiling Point: -61.7 °C (-79.1 °F)
• Phase at STP: Gas
• Electron Configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶
• Oxidation States: 0 (radon is chemically inert)

Chemical Properties

• Reactivity: Radon is the least reactive noble gas and is chemically inert under most conditions. It can, however, form compounds with highly electronegative elements like fluorine under extreme conditions.
• Compounds: Rare compounds include radon difluoride (RnF₂).

Uses and Applications

• Medical: Historically used in radiotherapy to treat cancer due to its radioactive properties.
• Scientific Research: Used as a source of alpha particles in various scientific experiments.
• Geological Research: Used in hydrology and geology to track the movement of groundwater and to study the behavior of faults.

Occurrence and Extraction

• Natural Occurrence: Radon is produced by the radioactive decay of uranium and thorium in the Earth’s crust. It is found in soil, rock, and water and can accumulate in buildings, particularly basements and lower floors.
• Extraction: Typically collected from the decay of radium salts or from natural gas.

Isotopes

• Stable Isotopes: Radon has no stable isotopes.
• Radioactive Isotopes: Radon-222 is the most stable and common isotope, with a half-life of 3.8 days. Other isotopes include Radon-220 and Radon-219, which are shorter-lived.

Safety and Handling

• Hazards: Radon is highly radioactive and a known carcinogen. It poses significant health risks when inhaled, contributing to lung cancer.
• Precautions: Adequate ventilation and radon mitigation systems should be used in buildings to reduce radon levels. Professional radon testing is recommended in areas with high radon concentrations.

History

• Discovery: Discovered by Friedrich Ernst Dorn in 1900.
• Name Origin: Named after the Latin word “radius,” meaning ray, reflecting its radioactive nature.

Additional Facts

• Crystal Structure: Face-centered cubic (fcc) when solid
• Magnetic Properties: Diamagnetic
• Thermal Conductivity: Low, about 3.61 mW·m⁻¹·K⁻¹
• Electrical Resistivity: Insulator (as a noble gas, it does not conduct electricity)

Summary

Radon is a radioactive noble gas produced by the decay of uranium and thorium. It is colorless and inert under normal conditions but can form compounds with highly electronegative elements. Radon has historical applications in medical radiotherapy and current uses in scientific and geological research. Due to its high radioactivity and carcinogenic properties, radon requires careful handling and mitigation to minimize exposure, particularly in indoor environments.

40 Question and Answer Pairs About Radon

1. What is the atomic number of Radon?

   • 86

2. What is the symbol for Radon?

   • Rn

3. What is the atomic weight of Radon?

   • [222] u (varies due to multiple isotopes)

4. In which group of the periodic table is Radon found?

   • Group 18

5. What period is Radon in?

   • Period 6

6. What block does Radon belong to?

   • p-block

7. What is the melting point of Radon?

   • -71 °C (-96 °F)

8. What is the boiling point of Radon?

   • -61.7 °C (-79.1 °F)

9. What is the density of Radon at 0 °C and 101.3 kPa?

   • 9.73 g/L

10. What is the electron configuration of Radon?

    • [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶

11. What are the common oxidation states of Radon?

    • 0 (chemically inert)

12. What is the appearance of Radon?

    • Colorless gas under normal conditions; glows yellow to orange-red when cooled below its freezing point

13. Is Radon reactive with air?

    • Radon is chemically inert under most conditions.

14. Name a compound of Radon.

    • Radon difluoride (RnF₂)

15. What is a common use of Radon in medicine?

    • Historically used in radiotherapy to treat cancer.

16. How is Radon used in scientific research?

    • Used as a source of alpha particles in various experiments.

17. What role does Radon play in geological research?

    • Used to track groundwater movement and study fault behavior.

18. How is Radon found in nature?

    • Produced by the radioactive decay of uranium and thorium in the Earth’s crust.

19. How is Radon typically collected?

    • From the decay of radium salts or from natural gas.

20. What is the most common isotope of Radon?

    • Radon-222

21. What safety hazard is associated with Radon?

    • It is a known carcinogen and poses significant health risks when inhaled.

22. Who discovered Radon?

    • Friedrich Ernst Dorn

23. Where does the name Radon come from?

    • From the Latin word “radius,” meaning ray.

24. What is the crystal structure of solid Radon?

    • Face-centered cubic (fcc)

25. Is Radon paramagnetic or diamagnetic?

    • Diamagnetic

26. What is the thermal conductivity of Radon?

    • About 3.61 mW·m⁻¹·K⁻¹

27. What is the electrical resistivity of Radon?

    • Insulator

28. What is the primary oxidation state of Radon?

    • 0 (chemically inert)

29. Is Radon found as a free element in nature?

    • Yes, in trace amounts as a gas.

30. What is the common name of Radon difluoride?

    • RnF₂

31. What is a major application of Radon in geological research?

    • Used to study groundwater movement and fault behavior.

32. How does Radon benefit medical research?

    • Used historically in radiotherapy for cancer treatment.

33. What is the boiling point of Radon in Kelvin?

    • 211.5 K

34. What group does Radon belong to in the periodic table?

    • Noble gases (Group 18)

35. What is the natural abundance of Radon-222?

    • Most common and stable isotope.

36. Can Radon be used in high-temperature applications?

    • No, due to its gaseous state and radioactivity.

37. What is the key property that makes Radon valuable in scientific research?

    • Its radioactivity and ability to emit alpha particles.

38. How is Radon used in radiation research?

    • As a source of alpha particles in various experiments.

39. What precautions should be taken when handling Radon?

    • Ensure proper ventilation and use radon mitigation systems to reduce exposure.

40. What makes Radon unique among the elements?

    • Its status as a highly radioactive noble gas with significant health risks.