Lead

Lead

CAS: 7439-92-1
Description: Soft, bluish-white metal
Classification: Other Metals
Date of Discovery: Known to the ancients
Discoverer: Unknown
Name Origin: Anglo-Saxon lead
Symbol Origin: Latin plumbum, "lead"

Atomic Number: 82
Number of Neutrons: 125
Atomic Mass: 207.2(1) amu
Melting Point: 327.46 °C
Boiling Point: 1749 °C
Density (293 K): 11.35 g/cm³
Atomic volume: 18.17 cm³/mol
Electrical resistivity: 0.0481 10^-6/cm

Thermal conductivity: 0.353 W/cmK
Enthalpy of atomization: 194.6 kJ/mol
Enthalpy of vaporization: 177.70 kJ/mol
Enthalpy of fusion: 4.799 kJ/mol
Specific heat capacity: 0.13 J/gK

Energy levels: 2-8-18-31-18-4
Electron configuration: [Xe]4f ¹⁴5d¹⁰6s²6p²
Crystal Structure: Cubic face centered
Atomic radius: 1.81 Å
Covalent radius: 1.47 Å
Oxidation States: +2, +4
Electronegativity, Pauling: 2.04
Electron affinity: 0.364 eV
First ionization energy: 7.416 eV
2nd ionization energy: 15.028 eV
3rd ionization energy: 31.943 eV
Polarizability: 6.8 10^-24cm³

Isotope	Natural Abundance	Atomic Mass	Half-life	Decay Mode	Spin
¹⁸²Pb	181.99268	0.06 s
¹⁸³Pb	182.9919	0.3 s		1/2+
¹⁸⁴Pb	183.9882	0.6 s		0+
¹⁸⁵Pb	184.9876	4.1 s
¹⁸⁶Pb	185.9835	5 s	⁺, EC;	0+
^187mPb	15.2 s	⁺, EC	(1/2-)
¹⁸⁷Pb	186.9839	18.3 s	EC;	13/2+
¹⁸⁸Pb	187.9811	23 s	EC;	0+
¹⁸⁹Pb	188.9809	51 s	EC;
¹⁹⁰Pb	189.9782	1.2 m	⁺; EC;	0+
^191mPb	2.2 m	⁺, EC	13/2+
¹⁹¹Pb	190.9782	1.3 m	⁺, EC
¹⁹²Pb	191.9758	3.5 m	⁺;	0+
^193mPb	5.8 m	⁺, EC	13/2+
¹⁹³Pb	192.9761	2 m	EC	3/2
¹⁹⁴Pb	193.9740	11 m	⁺, EC;	0+
^195mPb	15 m	⁺; EC	13/2+
¹⁹⁵Pb	194.976	15 m	⁺, EC
¹⁹⁶Pb	195.9727	37 m	⁺, EC	0+
¹⁹⁷Pb	196.9734	8 m	EC; ⁺	(3/2-)
¹⁹⁸Pb	197.9720	2.4 h	EC	0+
^199mPb	12.2 m	IT; ⁺, EC
¹⁹⁹Pb	198.9729	1.5 h	EC; ^-	5/2-
²⁰⁰Pb	199.97182	21.5 h	EC	0+
^201mPb	1.02 m	IT	13/2+
²⁰¹Pb	200.97285	9.33 h	EC	5/2-
^202mPb	3.53 h	IT; ⁺	9-
²⁰²Pb	201.97214	5.3 x 10⁴ y	EC	0+
^203mPb	6.2 s	IT	13/2+
²⁰³Pb	202.97338	2.1615 d	EC	5/2-
^204mPb	1.12 h	IT	9-
²⁰⁴Pb	1.4(1)	203.973028	Stable	0+
²⁰⁵Pb	204.974467	1.51 x 10⁷ y	EC	5/2-
²⁰⁶Pb	24.1(1)	205.974449	Stable	0+
^207mPb	0.80 s	IT	13/2+
²⁰⁷Pb	22.1(1)	206.975880	Stable	1/2-
²⁰⁸Pb	52.4(1)	207.976636	Stable	0+
²⁰⁹Pb	208.981075	3.25 h	^-	9/2+
²¹⁰Pb	209.984174	22.6 y	^-;	0+
²¹¹Pb	210.988732	36.1 m	^-	(9/2+)
²¹²Pb	211.991887	10.64 h	^-	0+
²¹³Pb	212.9966	10.2 m	^-
²¹⁴Pb	213.999797	26.9 m	^-	0+
Long known, mentioned in Exodus. The alchemists believed lead to be the oldest metal and associated it with the planet Saturn. Native lead occurs in nature, but it is rare. Lead is obtained chiefly from galena (PbS) by a roasting process. Anglesite (PbSO₄), cerussite (PbCO₃), and minim (Pb₃O₄) are other common lead minerals. Lead is a bluish-white metal of bright luster, is very soft, highly malleable, ductile, and a poor conductor of electricity. It is very resistant to corrosion; lead pipes bearing the insignia of Roman emperors, used as drains from the baths, are still in service. It is used in containers for corrosive liquids (such as sulfuric acid) and may be toughened by the addition of a small percentage of antimony or other metals. Natural lead is a mixture of four stable isotopes: ²⁰⁴Pb (1.4%), ²⁰⁶Pb (24.1 %), ²⁰⁷Pb (22.1 %), and ²⁰⁸Pb (52.4%). Lead isotopes are the end products of each of the three series of naturally occurring radioactive elements: ²⁰⁶Pb for the uranium series, ²⁰⁷Pb for the actinium series, and ²⁰⁸Pb for the thorium series. Forty other isotopes of lead, all of which are radioactive, are recognized. Its alloys include solder, type metal, and various antifriction metals. Great quantities of lead, both as the metal and as the dioxide, are used in storage batteries. Much metal also goes into cable covering, plumbing, ammunition, and in the manufacture of lead tetraethyl. The metal is very effective as a sound absorber, is used as a radiation shield around X-ray equipment and nuclear reactors, and is used to absorb vibration. White lead, the basic carbonate, sublimed white lead (PbSO₄) chrome yellow (PbCrO₄), red lead (Pb₃O₄), and other lead compounds are used extensively in paints, although in recent years the use of lead in paints has been drastically curtailed to eliminate or reduce health hazards. Lead oxide isused in producing fine "crystal glass" and "flint glass" of a high index of refraction for achromatic lenses. The nitrate and the acetate are soluble salts. Lead salts such as lead arsenate have been used as insecticides, but their use in recent years has been practically eliminated in favor of less harmful organic compounds. Care must be used in handling lead as it is a cumulative poison. Environmental concern with lead poisoning has resulted in a national program to eliminate the lead in gasoline. LINKS: EPA - Lead Hazard Info Pamphlet HUD Office of Lead Hazard Control Lead Poisoning Prevention Outreach Program Minerals Containing Lead Preventing Lead Poisoning in Young Children Return Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998.

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