Thulium (Tm)

General Information

• Symbol: Tm
• Atomic Number: 69
• Atomic Weight: 168.93422 u
• Element Category: Lanthanide
• Group: N/A (Lanthanides series)
• Period: 6
• Block: f-block

Physical Properties

• Appearance: Silvery-gray metallic
• Density: 9.32 g/cm³
• Melting Point: 1545 °C (2813 °F)
• Boiling Point: 1950 °C (3542 °F)
• Phase at STP: Solid
• Electron Configuration: [Xe] 4f¹³ 6s²
• Oxidation States: +3 (most common), +2

Chemical Properties

• Reactivity: Thulium is relatively stable in air but will tarnish slowly. It reacts with water to form thulium hydroxide and with acids to form thulium salts.
• Compounds: Forms compounds such as thulium(III) oxide (Tm₂O₃), thulium(III) chloride (TmCl₃), and thulium(III) nitrate (Tm(NO₃)₃).

Uses and Applications

• Lasers: Thulium-doped lasers are used in medical and dental procedures, especially in laser surgery.
• Portable X-ray Devices: Used in some portable X-ray machines as a radiation source.
• Nuclear Reactors: Used as a neutron absorber.
• Ceramics: Used in some ceramic materials and phosphors.
• High-Temperature Superconductors: Potentially useful in the development of high-temperature superconductors.

Occurrence and Extraction

• Natural Occurrence: Found in minerals such as monazite, bastnasite, and euxenite, often alongside other rare earth elements.
• Extraction: Extracted through complex processes involving the crushing of ore, magnetic separation, and solvent extraction.

Isotopes

• Stable Isotopes: Thulium-169 (the only naturally occurring isotope)
• Radioactive Isotopes: Several radioactive isotopes, including Thulium-171 and Thulium-170, used in research.

Safety and Handling

• Hazards: Thulium compounds are considered to have low toxicity, but dust and powders should be handled carefully to avoid inhalation or ingestion. Metallic thulium can be a fire hazard in powder form.
• Precautions: Use appropriate protective equipment when handling thulium and its compounds.

History

• Discovery: Discovered by Per Teodor Cleve in 1879.
• Name Origin: Named after Thule, an ancient name for Scandinavia.

Additional Facts

• Crystal Structure: Hexagonal close-packed (hcp)
• Magnetic Properties: Paramagnetic at room temperature; becomes ferromagnetic below 32 K
• Thermal Conductivity: 16.9 W/m·K
• Electrical Resistivity: 0.79 µΩ·m at 20°C

Summary

Thulium is a versatile lanthanide with a wide range of applications in industry, medicine, and technology. It is particularly valuable in laser surgery, portable X-ray devices, and potential high-temperature superconductors. Discovered in 1879 and named after the ancient name for Scandinavia, Thulium is found in several minerals and requires careful handling due to its reactive nature.

40 Question and Answer Pairs About Thulium

1. What is the atomic number of Thulium?

   • 69

2. What is the symbol for Thulium?

   • Tm

3. What is the atomic weight of Thulium?

   • 168.93422 u

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

   • Lanthanides series (no specific group)

5. What period is Thulium in?

   • Period 6

6. What block does Thulium belong to?

   • f-block

7. What is the density of Thulium?

   • 9.32 g/cm³

8. What is the melting point of Thulium?

   • 1545 °C (2813 °F)

9. What is the boiling point of Thulium?

   • 1950 °C (3542 °F)

10. What is the electron configuration of Thulium?

    • [Xe] 4f¹³ 6s²

11. What are the common oxidation states of Thulium?

    • +3 (most common), +2

12. What is the appearance of Thulium?

    • Silvery-gray metallic

13. Is Thulium reactive with air?

    • Relatively stable, tarnishes slowly.

14. Name a compound of Thulium.

    • Thulium(III) oxide (Tm₂O₃)

15. What is a common use of Thulium in lasers?

    • Thulium-doped lasers for medical procedures.

16. How is Thulium used in portable X-ray devices?

    • As a radiation source.

17. What role does Thulium play in nuclear reactors?

    • Used as a neutron absorber.

18. How is Thulium used in ceramics?

    • Used in some ceramic materials and phosphors.

19. What is a high-temperature application of Thulium?

    • Potential use in high-temperature superconductors.

20. How is Thulium typically found in nature?

    • In minerals such as monazite, bastnasite, and euxenite.

21. What is the most stable isotope of Thulium?

    • Thulium-169

22. What safety hazard is associated with Thulium dust?

    • It can be a fire hazard.

23. Who discovered Thulium?

    • Per Teodor Cleve

24. Where does the name Thulium come from?

    • Named after Thule, an ancient name for Scandinavia.

25. What is the crystal structure of Thulium at room temperature?

    • Hexagonal close-packed (hcp)

26. Is Thulium paramagnetic or diamagnetic at room temperature?

    • Paramagnetic

27. What is the thermal conductivity of Thulium?

    • 16.9 W/m·K

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

    • 0.79 µΩ·m

29. What is the primary oxidation state of Thulium in its compounds?

    • +3

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

    • No, it is found in minerals.

31. What is the common name of Thulium(III) chloride?

    • TmCl₃

32. What is a major application of Thulium in the medical field?

    • Thulium-doped lasers for surgery.

33. How does Thulium benefit the nuclear industry?

    • As a neutron absorber.

34. What is the melting point of Thulium in Kelvin?

    • 1818 K

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

    • Lanthanides series

36. What is the natural abundance of Thulium-169?

    • It is the only naturally occurring isotope.

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

    • Yes, particularly in superconductors.

38. What is the key property that makes Thulium valuable in lasers?

    • Its ability to emit specific wavelengths of light.

39. How is Thulium used in the chemical industry?

    • Mainly in research and specialized applications.

40. What precautions should be taken when handling Thulium?

    • Use appropriate protective equipment to avoid inhalation or ingestion.