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.
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.
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