Lead

Symbol: Pb
Atomic Number: 82
Atomic Weight: 207.2
Element Classification: Other Metal
Discovered By: Known to the ancients.
Discovery Date: n/a (Unknown)
Name Origin: Anglo-Saxon: lead; symbol from Latin: plumbum.

Density (g/cc): 11.35
Melting Point (K): 600.65
Boiling Point (K): 2013
Appearance: Very soft, highly malleable and ductile, blue-white shiny metal
Atomic Radius (pm): 175
Atomic Volume (cc/mol): 18.3
Covalent Radius (pm): 147
Ionic Radius: 84 (+4e) 120 (+2e)
Specific Heat (@20C J/g mol): 0.159
Fusion Heat (kJ/mol): 4.77
Evaporation Heat (kJ/mol): 177.8
Thermal Conductivity (@25C W/m K):
Debye Temperature (K): 88.00
Pauling Negativity Number: 1.8
First Ionizing Energy (kJ/mol): 715.2
Oxidation States: 4, 2
Electronic Configuration: [Xe] 4f14 5d10 6s2 6p2
Lattice Structure: Face-Centered Cubic (FCC)
Lattice Constant (): 4.950
Lattice C/A Ratio: n/a

Mineral Hardness [no units]: 1.5
Brinell Hardness [/MN m-2]: 38.3

Note: Lead is very soft and ductile and pure specimens are extremely difficult to prepare; however, lead alloys are considerably easier. Due to their low melting points, and low recrystallization temperatures, cold setting resins are usually recommended as recrystallization may occur during hot compression mounting. Heating of surfaces during grinding must be minimized. Grinding of these metals is always difficult, as SiC particles tend to embed heavily. Many authors have recommended coating the SiC paper surface with bees wax, but this does not solve the problem. Embedding is most common with the finer grit size papers. Diamond is not a very effective abrasive with these metals. Alumina works quite well.

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