what family are group does the element lead belong to
LEAD
Photograph by: Dreef
Overview
Lead is the heaviest member of the carbon family. The carbon family consists of the five elements in Group 14 (IVA) of the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Although a member of the carbon family, pb looks and behaves very differently from carbon.
Lead is one of only a few elements known to ancient peoples. I of the oldest examples of pb is a small statue found in Egypt. It was fabricated during the First Dynasty, in about 3400 B.C. Mention of lead and lead objects can also be constitute in very old writing from Bharat. And the Bible mentions atomic number 82 in a number of passages.
SYMBOL
Pb
Atomic NUMBER
82
ATOMIC MASS
207.2
Family unit
Group 14 (IVA)
Carbon
PRONUNCIATION
LED
Throughout history, Lead has been used to make water and sewer pipes; roofing; cable coverings; type metal and other alloys; paints; wrappings for food, tobacco, and other products; and as an condiment in gasoline. Since the 1960s, withal, there has been a growing concern about the health effects of lead. For example, scientists have establish that lead can cause mental and physical problems in growing children. Every bit a result, many common pb products are now existence phased out.
Discovery and naming
Lead has been around for thousands of years. Information technology is impossible to say when humans starting time discovered the element. It does not occur as an element in the earth very often. Merely i of its ores, atomic number 82 sulfide (PbS), is fairly common. Information technology is non difficult to obtain pure lead metal from pb sulfide. Humans probably discovered methods for doing so thousands of years ago.
By Roman times, lead metal was widely used. The far-reaching system that brought water to Rome independent many lead pipes. Sheets of pb were used as writing tablets and some Roman coins were also made of lead. Perhaps of greatest interest was the use of lead in making pots and pans. Modernistic scientists believe many Romans may have become ill and died because of this practice. Cooking liquids in pb utensils tends to brand the lead dissolve. It got into the food being cooked. People who ate those foods got more and more lead into their bodies. Somewhen, the effects of pb poisoning must have begun to appear.
Of form, the Romans had little agreement of the connection betwixt lead and illness. They probably never realized that they were poisoning themselves by using pb pots and pans.
No one is quite certain how atomic number 82 got its proper noun. The word has been traced to manuscripts that date to before the 12th century. Romans called the metallic plumbum. It is from this name that the chemical element's chemical symbol comes: Lead. Compounds of lead are sometimes called by this former name, such as plumbous chloride.
Physical properties
Pb is a heavy, soft, gray solid. Information technology is both ductile and malleable. Ductile means capable of being drawn into thin wires. Malleable means capable of being hammered into thin sheets. It has a shiny surface when starting time cut, but information technology slowly tarnishes (rusts) and becomes dull. Pb is hands worked. "Working" a metallic ways bending, cutting, shaping, pulling, and otherwise changing the shape of the metallic.
The melting betoken of atomic number 82 is 327.iv°C (621.3°F), and its boiling point is one,750 to 1,755°C (iii,180 to 3,190°F). Its density is 11.34 grams per cubic centimeter. Pb does not conduct an electrical current, audio, or vibrations very well.
Chemical properties
Pb is a moderately agile metal. It dissolves slowly in water and in most cold acids. It reacts more rapidly with hot acids. It does non react with oxygen in the air readily and does not burn.
Occurrence in nature
The affluence of lead in the World's chaff is estimated to be between thirteen and 20 parts per one thousand thousand. It ranks in the upper third among the elements in terms of its abundance.
Atomic number 82 rarely occurs equally a pure element in the earth. Its most common ore is galena, or lead sulfide (PbS). Other ores of Lead are anglesite, or pb sulfate (PbSO iv ); cerussite, or lead carbonate (PbCO 3 ); and mimetite (PbCL two ○ Pb 3 (AsO 4 ) two ).
The largest producers of pb ore in the earth are Commonwealth of australia, China, the United states, Peru, Canada, Mexico, and Sweden. In the United States, more than 93 pct of all the pb produced comes from Missouri. Other lead-producing states are Montana, Colorado, Idaho, Illinois, New York, and Tennessee. In 1996, 426,000 metric tons of lead were produced in the Us.
Isotopes
4 naturally occurring isotopes of pb occur. They are lead-204, lead-206, lead-207, and atomic number 82-208. Isotopes are 2 or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the correct of the element's name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the chemical element. The number of protons determines the element, only the number of neutrons in the atom of any i element can vary. Each variation is an isotope.
Almost xvi radioactive isotopes of lead are known also. A radioactive isotope is 1 that breaks autonomously and gives off some grade of radiations. Radioactive isotopes are produced when very modest particles are fired at atoms. These particles stick in the atoms and make them radioactive.
Romans routinely ate food cooked in lead pots and pans. The connection between lead and disease was not known then, so many people became ill and died of atomic number 82 poisoning.
One radioactive isotope of lead, pb-210, is sometimes used in medicine. This isotope gives off radiation that can kill cancer cells. It is also used to treat not-cancerous eye disorders.
Atomic number 82 smelting.
Extraction
Pb is obtained from its ores by a method used with many metals. First, the ore is roasted (heated in air). Roasting, also called smelting, converts the ore to a compound of atomic number 82 and oxygen, lead oxide (PbO ii ). Lead oxide is then heated with charcoal (pure carbon). The carbon takes oxygen away from the pb oxide. It leaves pure pb behind:
Lead obtained in this way is not very pure. Information technology can be purified electrolytically. Electrolytic refining involves passing an electric current through a compound. Very pure lead is nerveless at one side of the container in which the reaction is carried out.
A major source of lead is recycled car batteries.
Lead is also recovered in recycling programs. Recycling is the process past which a textile is retrieved from a product that is no longer used. For case, old car batteries were in one case merely thrown away. Now they are sent to recycling plants where lead tin can be extracted and used over and over again. It is non necessary to get all the atomic number 82 that industry needs from new sources, such as ores.
Uses
The lead industry is undergoing dramatic change. Many products once fabricated with lead no longer use the element. The purpose of this change is to reduce the amount of lead that gets into the environment. Examples of such products include ammunition, such every bit shot and bullets; sheet atomic number 82 used in building construction; solder; h2o and sewer pipes; ball bearings; radiation shielding; and gasoline. These changes are possible because manufacturers are finding safer elements to use in place of pb.
The price of a gallon of gas
F or many years, pb was regarded every bit a phenomenon chemical by the automotive manufacture. The power to run a car comes from the burning of gasoline in the engine. However, called-for gasoline is non a unproblematic process. Many things happen inside an engine when gasoline burns in the carburetor.
For instance, an engine can "knock" if the gasoline does not burn properly. "Knocking" is a "bang-bang" sound from the engine. It occurs when low-grade gasoline is used.
One style to prevent knocking is to use high-class gasoline. Another way is to add chemicals to the gasoline. The best gasoline additive discovered was a compound called tetraethyl atomic number 82 (Pb(C ii H 5 ) iv ). Tetraethyl atomic number 82 was usually called "lead" by the automotive manufacture, the consumer, and advertisers. When someone bought "leaded" gasoline, information technology contained not lead metal, but tetraethyl atomic number 82.
Leaded gasoline was a great discovery. It could exist made fairly cheaply and it prevented automobile engines from knocking. No wonder people thought it was a phenomenon chemical.
What people didn't realize was that tetraethyl atomic number 82 breaks down in a car engine because of the high temperature at which engines operate. When tetraethyl lead breaks downwards, elemental lead (Pb) is formed:
The outcome—with millions of cars being driven every day—was more and more lead getting into the air. And more and more than people inhaled that atomic number 82. Eventually, doctors began to see more than people with leadrelated diseases.
The federal government finally decided that tetraethyl lead was besides dangerous to utilize in gasoline. Past 1990, the apply of this compound had been banned past all governments in North America.
Other uses of pb have not declined. The best example is lead storage batteries. A atomic number 82 storage battery is a device for converting chemical energy into electric energy. Almost every car and truck has at least 1 lead storage battery. But no satisfactory substitute for it has been institute. Well-nigh 87 percent of all pb produced in the U.s. at present goes to the manufacture of lead storage batteries. In improver to cars and trucks, these batteries are used for communication networks and emergency power supplies in hospitals, and in forklifts, airline basis equipment, and mining vehicles.
Compounds
A modest percentage of lead is used to make pb compounds. Although the amount of atomic number 82 is small, the variety of uses for these compounds is large. Some examples of important lead compounds are:
lead acetate (Atomic number 82(C 2 H three O 2 ) ii ): insecticides; waterproofing; varnishes; dyeing of material; production of gold; hair dye
pb antimonate (Pb 3 (SbO 4 ) 2 ): staining of glass, porcelain and other ceramics
pb azide (Pb(N 3 ) 2 ): used as a "primer" for high explosives
lead chromate ("chrome yellow"; PbCrO 4 ): industrial paints (use restricted by police)
lead fluoride (PbF two ): used to make lasers; specialized optical glasses
lead iodide (PbI 2 ): photography; cloud seeding to produce pelting
pb naphthenate (Atomic number 82(C 7 H 12 O ii )): wood preservative; insecticide; additive for lubricating oil; paint and varnish drier
pb phosphite (2PbO ○ PbHPO 3 ): used to screen out ultraviolet radiations in plastics and paints
lead stearate (Atomic number 82(C xviii H 35 O 2 ) 2 ): used to make soaps, greases, waxes, and paints; lubricant; drier for paints and varnishes
lead telluride (PbTe): used to brand semiconductors, photoconductors, and other electronic equipment
Wellness effects
The health furnishings of lead have become much better understood since the middle of the 20th century. At one time, the metal was regarded equally quite rubber to use for almost applications. Now lead is known to cause both firsthand and long-term wellness problems, peculiarly with children. It is toxic when swallowed, eaten, or inhaled.
Young children are most at risk from lead poisoning. Some children have a condition known as pica. They have an abnormal want to eat materials similar dirt, paper, and chalk. Children with pica sometimes eat paint chips off walls. At one time, many interior house paints were fabricated with lead compounds. Thus, crawling babies or children with pica ran the hazard of eating big amounts of pb and being poisoned.
Some symptoms of pb poisoning include nausea, vomiting, farthermost tiredness, high blood pressure, and convulsions (spasms). Over a long period of time, these children ofttimes suffer encephalon harm. They lose the ability to carry out normal mental functions.
Other forms of pb poisoning can besides occur. For instance, people who work in factories where lead is used can inhale lead fumes. The amount of fumes inhaled at any one time may be minor. But over months or years, the atomic number 82 in a person'due south torso can build upwards. This kind of atomic number 82 poisoning can atomic number 82 to nerve impairment and problems with the gastrointestinal system (tum and intestines).
Lead causes both immediate and longterm health bug, especially with children. Information technology is toxic when swallowed, eaten, or inhaled.
Today, in that location is an effort to reduce the employ of atomic number 82 in consumer products. For instance, older homes are oft tested for atomic number 82 paint before they are resold. Atomic number 82 paint has besides been removed from older school buildings.
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Source: http://www.chemistryexplained.com/elements/L-P/Lead.html
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