Question

Element: LEAD

Expectations include but not limited to physical properties (color, density, refractive index, boiling point, melting point, crystal or amorphous, etc), absorption wavelength, chemical properties, density, refractive index (if exist)most common compounds it makes, availability in nature and in daily products we use, any significance forensic science.

Answer 1

element - lead

• Symbol - Pb
• Atomic no.- 82
• Latin name - plumbum
• Appearance (colour ) -metallic gray

• atomic weight - 207.2 u
• Group- 14 (carbon group)
• period 6 in periodic table(p-block)
• Electron configuration- [Xe] 4f14 5d10 6s2 6p2

• Physical properties - solid

• Melting point - 600.61 K ​(327.46 °C, ​621.43 °F)
• Boiling point- 2022 K ​(1749 °C, ​3180 °F)
• Density -11.34 g/cm3

when liquid (at m.p.)
10.66 g/cm3

• Oxidation states = −4, −2, −1, +1, +2, +3, +4 (an amphoteric oxide)
• Natural occurrence - primordial
• Crystal structure - ​face-centered cubic (fcc)
• Magnetic ordering - diamagnetic

• Main isotopes of lead -

  204Pb ( abundance - 1.4% )

  206Pb ( abundance - 24.1% )

  207Pb ( abundance - 22.1% )

  208Pb ( abundance - 52.4 % )

• Ore of lead - Galena

• Refractive index = 1.9

• Absorption WAVELENGTH: 283.3 nm.

• Availability in nature - Native lead is rare in nature. lead is usually found in ore with zinc, silver and copper and it is extracted together with these metals. The main lead mineral in Galena (PbS) and there are also deposits of cerrussite and anglesite which are mined.

• Use in daily life - Lead is widely used for car batteries, pigments, ammunition, cable sheathing, weights for lifting, weight belts for diving, lead crystal glass, radiation protection and in some solders. It is often used to store corrosive liquids.

• Chemical properties - Reactivity with water : Dissolves slowly in water.
  Oxidation : Does not readily react with oxygen in the air.
  Flammability : Does not burn.
  Reactivity with acids : Reacts quickly with hot acids but slowly to cold acids.

Lead metal reacts vigorously with fluorine, F2, at room temperature and chlorine, Cl2, on warming to form the poisonous dihalides lead(II) fluoride, PbF2, and lead(II) chloride, PbCl2, respectively.

• Physical properties - soft, highly malleable, ductile, and a relatively poor conductor of electricity. It is very resistant to corrosion but tarnishes upon exposure to air.