Lead

C
Aluminum Silicate Hydroxide
Al₂Si₂O₅(OH)₄

Lead is a poisonous metal that can damage nervous connections and cause blood and brain disorders.

The History Says

Lead has been used by humans for at least 7000 years.

The Present Scenario

Lead is a major constituent of the Lead-acid battery used extensively in car batteries.

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As a mineral, lead is very rare, though the element itself is somewhat common. Element lead occurs in concentration of about 13 parts per billion in the Earth's crust. Element lead do not form crystals of its own, hence the mineral lead is only rarely seen. Lead has been found with gold in placer deposits and in not so usual metamorphosed limestones and marbles. It is very soft and capable of being scratched by a fingernail.

Physical Properties of Lead

Color	Light-gray to slightly bluish-gray.
Streak	Light-gray. Streak shiny.
Hardness	1.5
Transparency	Opaque
Specific gravity	11.3
Luster	Metallic
Cleavage	None
Fracture	Hackly
Tenacity	Malleable, ductile, and sectile.
Density	11.4 gm/cm3

Chemical Properties of Lead

Melting point	600.65 K
Boiling point	2013 K
Heat of vapor	177.7 kJ/mol
Heat of fusion	4.799 kJ/mol
Specific heat	0.13 J/gm K

Atomic Properties of Lead

Atomic number	82
Atomic mass	207.2 u
Atomic radius	1.47 A
Electron configuration	(Xe)4f145d106s26p2
Covalent radius	1.81 A
Atomic volume	18.17 cm3/mol
Stable isotopes	4
Electronegativity	2.33

Uses of Lead

• In ammunition.
• As oxides in glass and ceramics.
• In metal casting.
• As sheet lead.
• As covering for cable.
• As caulking lead.
• In brass and bronze billets.
• In bearing metals.