Submitted To: Mr. Halpin
Submitted By: Jocelyn
Monday, December 7, 2009
Lead Poisoning/Health Effects
Lead is a poisonous metal. Before the 20th century, we did not know that lead was quite poisonous and that it was safe to use. Now we know that lead is toxic, it is not used as much. It can damage nerve connections and cause brain and blood disorders. We can be exposed to lead through these routes: inhalation, ingestion, and skin or eye contact. When in our bodies, it can affect these organs: eyes, gastrointestinal tract, central nervous system, kidneys, blood, and gingival tissue. Lead causes serious damage to our nervous system and our brains. Lead poisoning is a medical condition caused by increased levels of the lead in our bodies.
Sunday, December 6, 2009
The Discovery of Lead
Lead's discovery is unknown. Only the ancients know who it is and when it was discovered. The origin of the symbol for lead (Pb) is from the Latin word plumbum for soft metals. Metallic lead beads have been found in Çatalhöyük (modern-day Turkey) dating back to 6400 B.C.
Common Usage of Lead
Lead was used a lot until the discovery of lead poisoning. It is known and used for its high density and its ability against corrosion. Many products that use to use lead no longer do. People do not want lead to leak out into the environment. Examples of these include ammunition, sheet lead used in building construction, water and sewer pipes, ball bearings, and gasoline. Manufacturers are finding safer elements to use in the place of lead. Lead can be used for its metal form and its chemical compounds.
Some lead uses are:
- lead acid battery (car battery)
- colouring for ceramic glazes
- used in polyvinyl chloride (coats for electrical cords)
- projectiles for firearms
- fishing sinkers
- sheet lead for sound proof rooms
- shielding from radiation
- molten lead used for cooling
- roofing material, gutters and gutter joints, and on roof parapets
- some statues and sculptures
- to balance the wheel of a car
- solder
- ballast in boats
Physical Properties
Physical Properties
Lead is a soft and malleable but also ductile metal. It is also very heavy. It has a shiny surface when first cut, although it slowly tarnishes becoming very dull. Lead can be bent, cutted, shaped, and pulled. The hardness of lead is 1.5. It has a grey with slightly blue colour. It is opaque meaning you cannot see through it at all. Its density is 11.34 grams per cubic metre. The melting point of lead is 327.6°C (600.75K) and its boiling point is 1,740°C (2013K). Lead does not condust electric currents, sound, or vibration well. It is a solid.
chemical properties
Chemical Properties
Lead is a moderately active metal. It dissolves in most cold acid but more actively in hot acids. It dissolves slowly in water. Lead does not burn and does not react with oxygen.
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