chem

1. LEAD
Presented by : Jomz Soliveres

2. Lead

It is a chemical element in the carbon group
with its symbol Pb (derived from the Latin
name – Plumbum)

Its atomic number is 82

Its atomic mass is 207.2

Its melting point is 327.5 celcius

It is a soft and malleable metal with may be
regarded as a heavy and poor metal.

3. Continuation ... Lead

Metallic leads are bluish-white color after
being freshly cut

Later it turns to a dull greyish color when
exposed to the atmosphere.

Lead has a characteristic of being a shiny
chrome-silver luster whenever it is being
melted into liquid.

Lead has the highest atomic number of all
the stable elements in the periodic table.

4. Lead...
Lead has a certain degrees, although
poisonous susbtance to animals sometimes
including the humans.
It can destroy the humans' nervous system, or
even brain disorders. Excessive lead may
cause blood disorders to mammals.
Lead is also a neurotoxin that accumulates
both in soft tissues and bones
Lead poisoning had been reported to certain
countries like ancient Rome, Greece, China.

5. Uses of Lead

Lead's uses are building construction, lead-
acid batteries, bullets and shot, weights,
pewters, fusible alloys, and a radiation shield.

6. Characteristics of Lead
Lead is a bright and silvery metal with a very
slight shade of blue in a dry atmosphere.
With the contact of air, it begins to tarnish by
forming a complex mixture of compounds
depending on the condition around it.
Its few properties are: high density, softness,
ductility, malleability, poor electrical
conductivity compared to other metals, high
resistance of corrosion, and ability to react
with organic chemicals.

7. Chemical Reactivity
Lead is classified as a post-transposition
metal and is also part of the carbon group.
Lead only forms a protective oxide layer
although finely powdered highly purified can
ignite in the air.
Melted lead is oxidize in the air to lead
monoxide.

8. History
L
Lead has been commonly used for thousands of years
because it is widespread, easy to extract and easy to
work with. It is highly malleable as well as easy to smelt.
Metallic lead beads dating back to 6400 BCE have
been found in Çatalhöyük in modern-day Turkey. In the
early Bronze Age, lead was used with antimony and
arsenic.The largest preindustrial producer of lead was
the Roman economy, with an estimated annual output
of 80,000 tonnes, which was typically won as a by-
product of extensive silver smelting. Roman mining
activities occurred in Central Europe, Roman Britain,
the Balkans, Greece, Asia Minor and Hispania which
alone accounted for 40% of world production.

9. History...
Roman lead pipes often bore the insignia of Roman
emperors. Lead plumbing in the Latin West may have
been continued beyond the age of Theoderic the Great
into the medieval period. Many Roman "pigs" (ingots) of
lead figure in Derbyshire lead mining history and in the
history of the industry in other English centers. The
Romans also used lead in molten form to secure iron
pins that held together large limestone blocks in certain
monumental buildings. In alchemy, lead was thought to
be the oldest metal and was associated with the planet
Saturn. Alchemists accordingly used Saturn's symbol
(the scythe, ) to refer to le♄ ad.

10. History...
Up to the 17th century, tin was often not distinguished
from lead: lead was called Plumbum nigrum (literally,
"black lead"), while tin was called plumbum candidum
(literally, "bright lead"). Their inherence through history
can also be seen in other languages: the word "olovo"
means lead in Czech, but in Russian it ("олово")
means tin.Lead's symbol Pb is an abbreviation of its
Latin name plumbum for soft metals; the English
words "plumbing", "plumber", "plumb", and "plumb-
bob" also derive from this Latin root.

11. History...end
Lead production in the US commenced as early
as the late 1600s by Indians in the The
Southeast Missouri Lead District, commonly
called the Lead Belt, is a lead mining district in
the southeastern part of Missouri. Significant
among Missouri's lead mining concerns in the
district was the Desloge Family and Desloge
Consolidated Lead Company in Desloge,
Missouri and Bonne Terre – having been active
in lead trading, mining and lead smelting from
1823 in Potosi to 1929.

12. Health effects
Lead is a highly poisonous metal (regardless if inhaled
or swallowed), affecting almost every organ and system
in the body. The main target for lead toxicity is the
nervous system, both in adults and children. Long-term
exposure of adults can result in decreased performance
in some tests that measure functions of the nervous
system. Long-term exposure to lead or its salts
(especially soluble salts or the strong oxidant PbO2) can
cause nephropathy, and colic-like abdominal pains. It
may also cause weakness in fingers, wrists, or ankles.

13. Health Effects
Lead exposure also causes small increases in blood
pressure, particularly in middle-aged and older people and
can cause anemia. Exposure to high lead levels can
severely damage the brain and kidneys in adults or children
and ultimately cause death. In pregnant women, high levels
of exposure to lead may cause miscarriage. Chronic, high-
level exposure have shown to reduce fertility in males.
[ Lead also damages nervous connections (especially in
young children) and cause blood and brain disorders. Lead
poisoning typically results from ingestion of food or water
contaminated with lead; but may also occur after accidental
ingestion of contaminated soil, dust, or lead-based paint.

14. Health Effects
It is rapidly absorbed into the bloodstream and
is believed to have adverse effects on the
central nervous system, the cardiovascular
system, kidneys, and the immune system. The
component limit of lead is a test benchmark for
pharmaceuticals, representing the maximum
daily intake an individual should have. However,
even at this low level, a prolonged intake can be
hazardous to human beings. The treatment for
lead poisoning consists of dimercaprol and
succimer