Lead (Pb)

General Information

• Symbol: Pb
• Atomic Number: 82
• Atomic Weight: 207.2 u
• Element Category: Post-transition metal
• Group: 14
• Period: 6
• Block: p-block

Physical Properties

• Appearance: Bluish-white metallic, tarnishes to a dull gray when exposed to air
• Density: 11.34 g/cm³
• Melting Point: 327.5 °C (621.5 °F)
• Boiling Point: 1749 °C (3180 °F)
• Phase at STP: Solid
• Electron Configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²
• Oxidation States: +2 (most common), +4

Chemical Properties

• Reactivity: Lead is relatively unreactive. It forms a protective oxide layer when exposed to air. Reacts slowly with hydrochloric and sulfuric acids but dissolves readily in nitric acid.
• Compounds: Forms compounds such as lead(II) oxide (PbO), lead(II) chloride (PbCl₂), and lead(IV) oxide (PbO₂).

Uses and Applications

• Batteries: Widely used in lead-acid batteries for vehicles and backup power supplies.
• Radiation Shielding: Used as shielding against X-rays and gamma rays due to its high density.
• Ammunition: Historically used in bullets and shot.
• Construction: Used in roofing, pipes, and solder, although its use has declined due to health concerns.
• Pigments: Used in paints and pigments, such as lead white and red lead, although its use has been greatly reduced due to toxicity.

Occurrence and Extraction

• Natural Occurrence: Found in minerals such as galena (PbS), anglesite (PbSO₄), and cerussite (PbCO₃).
• Extraction: Extracted from galena through a process of roasting and reduction. The ore is heated in the presence of oxygen to produce lead oxide, which is then reduced with carbon to obtain lead metal.

Isotopes

• Stable Isotopes: Lead has four stable isotopes: Lead-204, Lead-206, Lead-207, and Lead-208.
• Radioactive Isotopes: Several radioactive isotopes, including Lead-210, used in scientific research.

Safety and Handling

• Hazards: Lead is highly toxic and can cause serious health issues, including neurological damage, anemia, and kidney damage. Lead exposure is particularly harmful to children.
• Precautions: Handle with extreme care, using appropriate protective equipment. Avoid inhalation, ingestion, and skin contact. Use in well-ventilated areas and follow safety guidelines for disposal.

History

• Discovery: Known to ancient civilizations; its use dates back to at least 7000 BCE.
• Name Origin: The name “lead” comes from the Old English word “lead,” and its symbol “Pb” is derived from the Latin word “plumbum.”

Additional Facts

• Crystal Structure: Face-centered cubic (fcc)
• Magnetic Properties: Diamagnetic
• Thermal Conductivity: Low, about 35.3 W/m·K
• Electrical Resistivity: High, about 208 nΩ·m at room temperature

Summary

Lead is a dense, bluish-white post-transition metal known for its historical use in batteries, radiation shielding, ammunition, construction, and pigments. Found primarily in the mineral galena, lead is extracted through roasting and reduction. Due to its high toxicity, lead requires careful handling and has seen reduced usage in many applications. Lead has been known and used by humans for thousands of years, with its symbol “Pb” derived from the Latin “plumbum.”

40 Question and Answer Pairs About Lead

1. What is the atomic number of Lead?

   • 82

2. What is the symbol for Lead?

   • Pb

3. What is the atomic weight of Lead?

   • 207.2 u

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

   • Group 14

5. What period is Lead in?

   • Period 6

6. What block does Lead belong to?

   • p-block

7. What is the melting point of Lead?

   • 327.5 °C (621.5 °F)

8. What is the boiling point of Lead?

   • 1749 °C (3180 °F)

9. What is the density of Lead?

   • 11.34 g/cm³

10. What is the electron configuration of Lead?

    • [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²

11. What are the common oxidation states of Lead?

    • +2, +4

12. What is the appearance of Lead?

    • Bluish-white metallic, tarnishes to a dull gray

13. Is Lead reactive with air?

    • Lead forms a protective oxide layer when exposed to air.

14. Name a compound of Lead.

    • Lead(II) oxide (PbO)

15. What is a common use of Lead in batteries?

    • Used in lead-acid batteries for vehicles.

16. How is Lead used in radiation shielding?

    • Used as shielding against X-rays and gamma rays.

17. What role does Lead play in ammunition?

    • Historically used in bullets and shot.

18. How is Lead used in construction?

    • Used in roofing, pipes, and solder.

19. What application does Lead have in pigments?

    • Used in paints such as lead white and red lead.

20. Name a mineral that contains Lead.

    • Galena (PbS)

21. How is Lead extracted from ores?

    • By roasting galena to produce lead oxide, then reducing it with carbon.

22. What is the most stable isotope of Lead?

    • Lead-208

23. Name a radioactive isotope of Lead used in research.

    • Lead-210

24. What safety hazard is associated with Lead?

    • Highly toxic and can cause serious health issues.

25. Where does the name Lead come from?

    • From the Old English word “lead.”

26. What is the crystal structure of Lead?

    • Face-centered cubic (fcc)

27. Is Lead paramagnetic or diamagnetic?

    • Diamagnetic

28. What is the thermal conductivity of Lead?

    • About 35.3 W/m·K

29. What is the electrical resistivity of Lead at room temperature?

    • About 208 nΩ·m

30. What is the primary oxidation state of Lead?

    • +2

31. Is Lead found as a free element in nature?

    • No, it is found in minerals like galena.

32. What is the common name of Lead(IV) oxide?

    • PbO₂

33. What is a major application of Lead(II) chloride?

    • Used in lead-acid batteries.

34. How does Lead benefit radiation shielding?

    • Its high density makes it effective in blocking X-rays and gamma rays.

35. What is the boiling point of Lead in Kelvin?

    • 2022 K

36. What group does Lead belong to in the periodic table?

    • Post-transition metals

37. What is the natural abundance of Lead-208?

    • About 52.4%

38. Can Lead be used in high-temperature applications?

    • Yes, in certain specialized high-temperature alloys.

39. What is the key property that makes Lead valuable in construction?

    • Its durability and resistance to corrosion.

40. What precaution should be taken when handling Lead?

    • Handle with extreme care, using appropriate protective equipment to avoid exposure.