Radium (Ra)

General Information

• Symbol: Ra
• Atomic Number: 88
• Atomic Weight: [226] u (varies due to multiple isotopes)
• Element Category: Alkaline earth metal
• Group: 2
• Period: 7
• Block: s-block

Physical Properties

• Appearance: Silvery-white metallic; oxidizes to black when exposed to air
• Density: 5.5 g/cm³
• Melting Point: 700 °C (1292 °F)
• Boiling Point: 1737 °C (3159 °F)
• Phase at STP: Solid
• Electron Configuration: [Rn] 7s²
• Oxidation States: +2 (most common)

Chemical Properties

• Reactivity: Radium is highly reactive, more so than barium. It reacts with water to form radium hydroxide and with air to form radium nitride and radium oxide.
• Compounds: Forms compounds such as radium chloride (RaCl₂), radium bromide (RaBr₂), and radium sulfate (RaSO₄).

Uses and Applications

• Medical: Historically used in radiotherapy for cancer treatment and in luminous paints for watches, clocks, and instrument dials.
• Scientific Research: Used as a source of radon gas and in research on radioactivity and atomic structure.
• Radiography: Used in industrial radiography to inspect materials and structures.

Occurrence and Extraction

• Natural Occurrence: Found in uranium and thorium ores, particularly in the minerals uraninite and carnotite. It is produced as a decay product of uranium-238.
• Extraction: Extracted from uranium ores through a series of chemical processes, including precipitation and purification.

Isotopes

• Stable Isotopes: Radium has no stable isotopes.
• Radioactive Isotopes: Radium-226 is the most stable isotope with a half-life of 1600 years. Other isotopes include Radium-223, Radium-224, and Radium-228.

Safety and Handling

• Hazards: Radium is highly radioactive and poses severe health risks, including bone cancer and other radiation-related diseases. It emits alpha, beta, and gamma radiation.
• Precautions: Handle with extreme caution using specialized protective equipment and facilities designed to contain radioactivity. Radium must be stored in lead containers to shield against radiation.

History

• Discovery: Discovered by Marie and Pierre Curie in 1898.
• Name Origin: Named after the Latin word “radius,” meaning ray, reflecting its intense radioactivity.

Additional Facts

• Crystal Structure: Body-centered cubic (bcc)
• Magnetic Properties: Non-magnetic
• Thermal Conductivity: Moderate, about 18.6 W/m·K
• Electrical Resistivity: Relatively high, about 1 µΩ·m at 20 °C

Summary

Radium is a highly radioactive alkaline earth metal known for its historical use in cancer treatment and luminous paints. It is found in uranium and thorium ores and extracted through chemical processes. Radium’s intense radioactivity makes it valuable in scientific research and industrial radiography but also requires careful handling and specialized safety precautions to prevent exposure. Discovered by Marie and Pierre Curie, radium’s name reflects its powerful radioactive properties.

40 Question and Answer Pairs About Radium

1. What is the atomic number of Radium?

   • 88

2. What is the symbol for Radium?

   • Ra

3. What is the atomic weight of Radium?

   • [226] u

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

   • Group 2 (Alkaline earth metals)

5. What period is Radium in?

   • Period 7

6. What block does Radium belong to?

   • s-block

7. What is the melting point of Radium?

   • 700 °C (1292 °F)

8. What is the boiling point of Radium?

   • 1737 °C (3159 °F)

9. What is the density of Radium?

   • 5.5 g/cm³

10. What is the electron configuration of Radium?

    • [Rn] 7s²

11. What are the common oxidation states of Radium?

    • +2

12. What is the appearance of Radium?

    • Silvery-white metallic; oxidizes to black when exposed to air

13. Is Radium reactive with air?

    • Yes, it forms radium nitride and radium oxide.

14. Name a compound of Radium.

    • Radium chloride (RaCl₂)

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

    • Historically used in radiotherapy for cancer treatment.

16. How is Radium used in scientific research?

    • As a source of radon gas and in research on radioactivity.

17. What role does Radium play in industrial radiography?

    • Used to inspect materials and structures.

18. How is Radium found in nature?

    • In uranium and thorium ores.

19. How is Radium extracted from ores?

    • Through chemical processes, including precipitation and purification.

20. What is the most stable isotope of Radium?

    • Radium-226

21. What is the half-life of Radium-226?

    • 1600 years

22. What safety hazard is associated with Radium?

    • It is highly radioactive and poses severe health risks.

23. Who discovered Radium?

    • Marie and Pierre Curie

24. Where does the name Radium come from?

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

25. What is the crystal structure of Radium?

    • Body-centered cubic (bcc)

26. Is Radium magnetic?

    • No, it is non-magnetic.

27. What is the thermal conductivity of Radium?

    • About 18.6 W/m·K

28. What is the electrical resistivity of Radium at 20 °C?

    • About 1 µΩ·m

29. What is the primary oxidation state of Radium?

    • +2

30. Is Radium found as a free element in nature?

    • No, it is found in minerals.

31. What is the common name of Radium sulfate?

    • RaSO₄

32. What is a major application of Radium bromide (RaBr₂)?

    • Used in luminous paints.

33. How does Radium benefit medical applications?

    • Historically used in cancer treatment radiotherapy.

34. What is the boiling point of Radium in Kelvin?

    • 2010 K

35. What group does Radium belong to in the periodic table?

    • Alkaline earth metals (Group 2)

36. What is the natural abundance of Radium-226?

    • Extremely rare, produced from uranium decay.

37. Can Radium be used in high-temperature applications?

    • No, due to its radioactivity.

38. What is the key property that makes Radium valuable in scientific research?

    • Its intense radioactivity.

39. How is Radium used in radiation research?

    • As a source of radon gas and alpha particles.

40. What precautions should be taken when handling Radium?

    • Use specialized protective equipment and facilities to contain radioactivity.