Lead
Lead is a chemical element with the symbol Pb and atomic number 82. It has a standard atomic weight of 207.2, sits in period 6 and group 14, and is classified as a post-transition metal.
Properties
| Symbol | Pb |
|---|---|
| Atomic number | 82 |
| Standard atomic weight | 207.2 |
| Category | Post-transition metal |
| Group | 14 |
| Period | 6 |
| Electron configuration | [Xe] 4f14 5d10 6s2 6p2 |
| Outer-shell electrons | 4 |
The figure of 207.2 is a conventional value, because IUPAC publishes an interval for this element rather than a single weight. For elements like this one the fourth digit carries real uncertainty, because the isotopic composition varies measurably between natural sources — so quoting eight digits would overstate what is known.
Compounds containing lead
3 of the compounds in this reference contain Pb, listed by the fraction of their mass it makes up.
| Compound | Formula | Atoms | % by mass |
|---|---|---|---|
| lead oxide | OPb | 1 | 92.8% |
| galena | PbS | 1 | 86.6% |
| lead nitrate | N2O6Pb | 1 | 62.6% |
Calculate with lead
- Molar mass of any formula containing it
- Electron configuration, including ions
- Effective nuclear charge by Slater's rules
- Average atomic mass from isotope abundances
Group 14
Atomic weights are the IUPAC 2021 standard values, abridged to the conventional five significant figures. Group, period, category and electron configuration are derived from the atomic number rather than stored, so they cannot drift out of step with it.