Lead (Pb)
Lead (Pb) is a post-transition metal with atomic number 82 and a standard atomic weight of 207.2. At room temperature it is a solid that melts at 327 °C and boils at 1,749 °C.
Lead key facts
Lead at a glance
Identity
| Symbol | Pb |
|---|---|
| Atomic number (Z) | 82 |
| Atomic weight | 207.2 ± 1.1 (CIAAW 2024) |
| Category | Post-transition metal |
| Group | 14 — carbon group |
| Period | 6 |
| Block | p-block |
| CAS number | 7439-92-1 |
Atomic properties
| Electron configuration | [Xe] 4f14 5d10 6s2 6p2 Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p2 |
|---|---|
| Electrons per shell | 2, 8, 18, 32, 18, 4 |
| Oxidation states | +2, +4 Less common: -4, -2, -1, 0, +1, +3 |
| Electronegativity (Pauling) | 2.33 |
| First ionisation energy | 7.417 eV (715.6 kJ/mol) 2nd: 15.033 eV · 3rd: 31.937 eV |
| Electron affinity | 0.357 eV |
| Atomic radius (empirical) | 180 pm |
| Covalent radius | 144 pm |
| Van der Waals radius | 202 pm |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Melting point | 327.5 °C · 621.4 °F · 600.61 K |
| Boiling point | 1,749 °C · 3,180.2 °F · 2,022.15 K |
| Density | 11.3 g/cm³ |
| Specific heat capacity | 0.13 J/(g·K) |
| Thermal conductivity | 35.3 W/(m·K) |
| Crystal structure | Face-centred cubic |
Isotopes & abundance
| Natural occurrence | Primordial |
|---|---|
| Radioactive | No |
| Natural isotopes (abundance) | 208Pb 52.4%, 206Pb 24.1%, 207Pb 22.1%, 204Pb 1.4% |
| Stable isotopes | 4 |
| Known isotopes | 43 |
| Abundance in Earth's crust | 14 mg/kg |
| Abundance in seawater | 0.00003 mg/L |
Atomic weights: CIAAW Abridged Standard Atomic Weights 2024. Other properties: standard reference compilations, checked October 2026; predicted values are marked.
Lead electron configuration
Lead has 82 electrons. Written in short form, its ground-state configuration is [Xe] 4f14 5d10 6s2 6p2 — the electrons of the noble gas xenon, plus 4f14 5d10 6s2 6p2.Written out in full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p2.
As a member of group 14 it has 4 valence electrons in its outer shell (shell 6), which largely decide its chemistry.
Discovery and name
Prehistoric — Known since antiquity.
Anglo-Saxon lead; the symbol Pb is from Latin plumbum.
Known for
Dense and easy to work; used in car batteries, radiation shielding and, historically, pipes and paint. Its use is restricted because it is toxic.
Isotopes of lead
Naturally occurring lead is a mix of 4 isotopes. Each has 82 protons; they differ in the number of neutrons:
| Isotope | Protons | Neutrons | Natural abundance | Stability |
|---|---|---|---|---|
| 208Pb | 82 | 126 | 52.4% | stable |
| 206Pb | 82 | 124 | 24.1% | stable |
| 207Pb | 82 | 125 | 22.1% | stable |
| 204Pb | 82 | 122 | 1.4% | stable |
43 isotopes of lead are known in our data set (half-lives as published in nuclear data tables).
Lead compared with group 14
The other elements in group 14 (carbon group), from top to bottom of the table:
| Element | Z | Atomic weight | Melting point | Boiling point | Density | Electronegativity |
|---|---|---|---|---|---|---|
| Carbon | 6 | 12.011 | — | 3,642 °C | 2.2 g/cm³ | 2.55 |
| Silicon | 14 | 28.085 | 1,414 °C | 3,265 °C | 2.33 g/cm³ | 1.9 |
| Germanium | 32 | 72.630 | 938 °C | 2,833 °C | 5.323 g/cm³ | 2.01 |
| Tin | 50 | 118.71 | 232 °C | 2,586 °C | 7.287 g/cm³ | 1.96 |
| Lead | 82 | 207.2 | 327 °C | 1,749 °C | 11.3 g/cm³ | 2.33 |
| Flerovium | 114 | [290] | — | — | 9.928 g/cm³ (pred.) | — |