'Zijun'+Lead+-+Not+found+in+pencils

__ Lead __  Symbol: Pb (from Latin //plumbium//)  Position in periodic table: Group 14, period 6  Elemental category: post-transition metal  Atomic number: 82  Atomic weight: 207.2 g/mol  Electronic configuration: 2,8,18,32,18,4  Density: 11.34 g/cm3 at r.t.     Melting point: 327.46 °C  Boiling point: 1749 °C  Electrical resistance: 208 nΩ·m  Thermal conductivity: 35.3 W/m/K



(Above) Lead in its raw form (Below) The electronic configuration of lead

Lead is a soft malleable poor metal, has low electrical conductivity and is highly resistant from corrosion. For these properties, lead is very useful and can be used in many ways. Lead is very hard to find in nature, and is usually found with other metals such as zinc, silver and copper and therefore has to be refined. __ Application of lead __ 

 Car batteries Contain lead which is necessary for the chemical reaction which produces electricity

Bullets <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 0px;">Gun ammo such as shotgun shells contains lead as lead has a low melting point and therefore is easily cast for production of small arms ammo and shotgun pellets.

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Roofs or other outdoor usage Lead is good for water-proofing usage as it is highly resistant to corrosion and will not become damaged due to nature.

Radioactive shielding Lead can be used as shielding from radiation



__ Health effects of lead __ When ingested, lead can cause several unwanted effects, such as: - Disruption of the biosynthesis of haemoglobin and anaemia - A rise in blood pressure - Kidney damage - Miscarriages and subtle abortions - Disruption of nervous systems - Brain damage - Declined fertility of men through sperm damage - Diminished learning abilities of children - Behavioural disruptions of children, such as aggression, impulsive behaviour and hyperactivity Lead can enter a foetus through the placenta of the mother. Because of this it can cause serious damage to the nervous system and the brains of unborn children. Unfortunately, we are exposed to lead very often and an absorb it in the following ways 1. Through food. Lead is found in almost all foods as airborne lead particles can land on them and contaminate them, or they naturally contain lead. 2. Through air. Industries which process or use lead will release lead particles into the air which can be breathed in. 3. Through paint contamination. The paint in your home may contain lead and when it peels lead particles are released and may contaminate what you consume or enter through hand-mouth contact. References: 1. [] 2. [] 3. [] 4. [] 5. [] 6. [|http://www.freewebs.com] 7. [|http://www.answers.com] 8. [] 9. http://t3.gstatic.com/images?q=tbn:ANd9GcSxfe0uHsrly5s5bLC5d54uwgFyvYKHwmh9j37FvPj4SKsw89J1nA