Holmium (Ho)

General Information

• Symbol: Ho
• Atomic Number: 67
• Atomic Weight: 164.93033 u
• Element Category: Lanthanide
• Group: N/A (Lanthanides series)
• Period: 6
• Block: f-block

Physical Properties

• Appearance: Silvery-white metallic
• Density: 8.79 g/cm³
• Melting Point: 1474 °C (2685 °F)
• Boiling Point: 2700 °C (4892 °F)
• Phase at STP: Solid
• Electron Configuration: [Xe] 4f¹¹ 6s²
• Oxidation States: +3 (most common)

Chemical Properties

• Reactivity: Holmium is relatively stable in dry air but oxidizes in moist air, forming a yellowish oxide layer. It reacts with water to form holmium hydroxide and with acids to form holmium salts.
• Compounds: Forms compounds such as holmium(III) oxide (Ho₂O₃), holmium(III) chloride (HoCl₃), and holmium(III) nitrate (Ho(NO₃)₃).

Uses and Applications

• Magnets: Used in high-strength permanent magnets and in certain magnetic alloys.
• Lasers: Holmium-doped crystals are used in solid-state lasers, particularly in medical and dental procedures.
• Nuclear Reactors: Used as a neutron absorber in nuclear reactors.
• Coloring Glass and Ceramics: Holmium oxide is used to color glass and ceramics, producing a yellow or red color.
• Magnetic Field Generators: Holmium has the highest magnetic moment of any naturally occurring element and is used in magnetic field applications.

Occurrence and Extraction

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

Isotopes

• Stable Isotopes: Holmium-165 (the only naturally occurring isotope)
• Radioactive Isotopes: Several radioactive isotopes, including Holmium-163 and Holmium-166, used in research.

Safety and Handling

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

History

• Discovery: Discovered by Marc Delafontaine and Jacques-Louis Soret in 1878, and independently by Per Teodor Cleve in 1879.
• Name Origin: Named after the Latin name for Stockholm, “Holmia.”

Additional Facts

• Crystal Structure: Hexagonal close-packed (hcp)
• Magnetic Properties: Paramagnetic at room temperature; ferromagnetic below 19 K
• Thermal Conductivity: 16.2 W/m·K
• Electrical Resistivity: 0.79 µΩ·m at 20°C

Summary

Holmium is a versatile lanthanide with a wide range of applications in industry, medicine, and research. It is particularly valuable in high-strength magnets, solid-state lasers, and nuclear reactors. Discovered in the late 19th century and named after Stockholm, holmium is found in several minerals and requires careful handling due to its reactive nature.

40 Question and Answer Pairs About Holmium

1. What is the atomic number of Holmium?

   • 67

2. What is the symbol for Holmium?

   • Ho

3. What is the atomic weight of Holmium?

   • 164.93033 u

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

   • Lanthanides series (no specific group)

5. What period is Holmium in?

   • Period 6

6. What block does Holmium belong to?

   • f-block

7. What is the density of Holmium?

   • 8.79 g/cm³

8. What is the melting point of Holmium?

   • 1474 °C (2685 °F)

9. What is the boiling point of Holmium?

   • 2700 °C (4892 °F)

10. What is the electron configuration of Holmium?

    • [Xe] 4f¹¹ 6s²

11. What are the common oxidation states of Holmium?

    • +3 (most common)

12. What is the appearance of Holmium?

    • Silvery-white metallic

13. Is Holmium reactive with air?

    • Yes, it oxidizes in moist air.

14. Name a compound of Holmium.

    • Holmium(III) oxide (Ho₂O₃)

15. What is a common use of Holmium in magnets?

    • Used in high-strength permanent magnets.

16. How is Holmium used in the medical field?

    • In holmium-doped lasers for medical and dental procedures.

17. What role does Holmium play in nuclear reactors?

    • Used as a neutron absorber.

18. How is Holmium used in coloring glass and ceramics?

    • Holmium oxide is used to produce yellow or red colors.

19. What is a magnetic field application of Holmium?

    • Used in magnetic field generators.

20. How is Holmium typically found in nature?

    • In minerals such as monazite and bastnasite.

21. What is the most stable isotope of Holmium?

    • Holmium-165

22. What safety hazard is associated with Holmium dust?

    • It can be a fire hazard.

23. Who discovered Holmium?

    • Marc Delafontaine and Jacques-Louis Soret, independently by Per Teodor Cleve.

24. Where does the name Holmium come from?

    • Named after the Latin name for Stockholm, “Holmia.”

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

    • Hexagonal close-packed (hcp)

26. Is Holmium paramagnetic or diamagnetic at room temperature?

    • Paramagnetic

27. What is the thermal conductivity of Holmium?

    • 16.2 W/m·K

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

    • 0.79 µΩ·m

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

    • +3

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

    • No, it is found in minerals.

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

    • HoCl₃

32. What is a major application of Holmium in the magnet industry?

    • High-strength permanent magnets.

33. How does Holmium benefit the nuclear industry?

    • As a neutron absorber in reactors.

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

    • 1747 K

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

    • Lanthanides series

36. What is the natural abundance of Holmium-165?

    • It is the only naturally occurring isotope.

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

    • Yes, particularly in magnets and alloys.

38. What is the key property that makes Holmium valuable in magnets?

    • Its high magnetic moment.

39. How is Holmium used in the chemical industry?

    • Mainly in research and specialized applications.

40. What precautions should be taken when handling Holmium?

    • Use appropriate protective equipment to avoid inhalation or ingestion.