Lead

Symbol PbAtomic number 82
Atomic mass
207.2
Thermal conductivity
0.353
Atomic radius
1.47
Covalent radius
1.81
Density
11.4
Atomic volume
18.17
Melting point
600.65
Oxidation states
4,2
Boiling point
2013
Stable isotopes
4
Heat of vapor.
177.7
Electronegativity
2.33
Heat of fusion
4.799
First ionization
7.416
Specific heat
0.13
Electrical conduct.
4.5
Electron configuration

General descriptionNuclear data
Index

Periodic Table

Chemistry concepts
 
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Lead

Lead is a soft, heavy, dull gray metal with low tensile strength. It is used in making type, for covering electrical cables, and in many alloys. The organic lead compound tetraethyl lead, Pb(C2H5)4, was widely used as a gasoline additive to prevent knock in automobile until concern about lead toxicity caused that use to be discontinued.

Lead forms a thin surface layer of oxide in air, which slowly changes to a basic carbonate. Hard water forms a similar coating on lead, which protects the water from further contamination with soluble lead compounds. Soft water dissolves appreciable amounts of lead, which is poisonous.

Lead monoxide, PbO, called litharge is made by heating lead in air. It is a yellow powder or yellowish-red crystalline material which is used in making lead glass.

Red lead, Pb3O4, can be made by heating lead in oxygen. It is used in glass making and for making a red paint for protecting iron and steel structures.

Lead dioxide, PbO2, is widely used in lead storage batteries. The mineral form of lead dioxide is called Plattnerite.

White lead is a basic carbonate of lead, Pb3(OH)2(CO3)2, which was widely used as a white pigment in paint until concerns about lead toxicity brought a halt to most such uses. Lead carbonate, PbCO3, in mineral form is called cerussite. Lead chromate, PbCrO4, is also used as a pigment under the name chrome yellow. A brilliant red-orange color is exhibited by the mineral crocoite, a mineral form of PbCrO4.

Lead in its metallic form is widely used for radiation shielding because of its high absorption constant for x-rays and gamma-rays.

Lead occurs naturally in the sulfide mineral galena (PbS) and occurs with vanadium in vanadinite. A carbonate form of lead is phosgenite. Lead sulfate, PbSO4, in the mineral form anglesite is sometimes of gem quality. Lead forms an oxide mineral with titanium, iron and manganese called senaite. Lead forms a sulfide with antimony and iron called Jamesonite and sulfides with antimony called zinkenite, plagionite, semseyite and boulangerite. Dufrenoysite and gratonite are sulfides of lead with arsenic. A sulfide formed with antimony and arsenic is called jordanite. A sulfide formed with tin, iron and antimony is called cylindrite. Bournonite is a sulfide with copper, lead and antimony. Lead is found in the mineral nagyagite, a sulfide, along with gold, iron, antimony, and tellurium. Silver joins with lead and antimony in the sulfide andorite, AgPbSb3S6. Lead, copper and iron join in the sulfide betekhtinite. In the sulfide mineral hutchinsonite,(Tl, Pb)2As5S9 , lead joins with arsenic and thallium. One mineral form of selenium is the compound with lead, clausthalite, PbSe.

Beudantite is a mineral containing iron and lead along with sulfate and arsenate groups, PbFe3(AsO4,SO4)2(OH)6. A striking green color is exhibited by the mineral bayldonite which combines copper, zinc and lead with an arsenate group. The phosphate mineral pyromorphite , Pb5(PO4)3Cl, also exhibits a green color although it also appears in browns, reds and yellows.

Lead is one of the few elements which can be found in nature in pure form. This sample of lead with pyrochroite is displayed in the Smithsonian Museum of Natural History. The large sample is about 18x30 cm and is from Langban Mine, Filipstad, Varmland, Sweden.

Atomic dataNuclear data
Index

Periodic Table

Chemistry concepts

Reference
Pauling
Ch. 26
 
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Lead Nuclear Data

Z
A
Atomic
Mass (u)
Nuclear
Mass(GeV/c2
Binding
Energy(MeV)
Spin
Natural
Abund.
Half-life
Decay
Q
MeV
82
204
203.973020
189.9593
1607.6
0
0.0014
stable
...
...
82
205
204.974458
190.8921
1614.3
5/2
...
15.1My
EC
0.053
82
206
205.974440
191.8236
1622.4
0
0.241
stable
...
...
82
207
206.975871
192.7565
1629.1
1/2
0.221
stable
...
...
82
208
207.976627
193.6887
1636.5
0
0.524
stable
...
...
82
209
208.981065
194.6243
1640.4
9/2
...
3.25h
b-
0.64
82
210
209.984163
195.5587
1645.6
0
...
22.6y
b-
0.063
82
211
210.988735
196.4944
1649.4
9/2
...
36.1m
b-
1.38
82
212
211.991871
197.4289
1654.6
0
...
10.64h
b-
0.57
82
214
213.999798
199.2993
1663.3
0
...
26.8m
b-
1.03
Atomic data
Index

Periodic Table

Chemistry concepts

Reference
Rohlf
 
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