WebElements

Periodic Table

lead

Atomic number: 82
Atomic weight: 207.2
Symbol: Pb
Group number: 14
Electronic configuration: [Xe].4f14.5d10.6s2.6p2

Description

Lead is a bluish-white lustrous metal. It is very soft, highly malleable, ductile, and a relatively poor conductor of electricity. It is very resistant to corrosion but tarnishes upon exposure to air. Lead pipes bearing the insignia of Roman emperors, used as drains from the baths, are still in service. Alloys include pewter and solder. Tetraethyl lead (PbEt4) is still used in some grades of petrol (gasoline) but is being phased out on environmental grounds.

Lead isotopes are the end products of each of the three series of naturally occurring radioactive elements.

General information

Discoveror: Known to ancients
Date discovered:
Discovered at: n.a.
Meaning of name: From the Anglo-Saxon word "lead; Latin, plumbum" (the origin of the symbol Pb is the Latin word "plumbum" meaning "liquid silver"

Physical data

Standard state: solid at 298 K
Colour: bluish white
Density of solid at ambient temperature/kg m-3: 11340
Molar volume/cm3: 18.26

Radii /pm

Atomic: 154
Covalent (single bond):
Pauling radius for the ion [Pb]-: no data

Valence shell orbital radius maxima (Rmax)
orbital s p d f
radius121.2148.256.218.3

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 2.1
Allred Rochow: 1.5

Crystal Structure

structure: ccp (cubic close-packed)

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

ball-and-stick.gif

Temperatures (/K)

melting point: 600.61
boiling point: 2022

Enthalpies /kJ mol-1

fusion: 4.77
vaporization: 178

single bond enthalpies:
Pb-F Pb-Cl Pb-Br Pb-I Pb-Pb
331 243 201 205 161.5

Ionization enthalpies /kJ mol-1

Number Enthalpy
1st715.5
2nd1450.4
3rd3081.5
4th4080
5th6640

Isotopes

This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
204Pb203.973020 (5)1.4 (1)
206Pb205.974440 (4)24.1 (1)
207Pb206.975872 (4)22.1 (1)
208Pb207.976627 (4)52.4 (1)

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Pb.html