Lead
Element 82 · Post-Transition Metal
Lead is heavy, soft enough to scratch with a fingernail, and melts easily — qualities humans have exploited for millennia, from Roman water pipes to modern car batteries. Its density also makes it the standard shield against X-rays and gamma rays.
The same chemistry that made lead useful makes it hazardous: it accumulates in the body and harms the nervous system, especially in children. That is why lead has been removed from petrol, paint, and plumbing, though billions of lead-acid batteries are still recycled each year.
Key facts
| Atomic number | 82 |
|---|---|
| Atomic weight | 207.2 |
| Category | Post-Transition Metal |
| Group / Period | 14 / 6 |
| Block | p |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p2 |
| Common oxidation states | +2, +4 |
| State at STP | Solid |
| Electronegativity | 2.33 |
| Density | 11.34 g/cm³ |
| Melting point | 327.46 °C |
| Boiling point | 1749 °C |
Occurrence
Lead is mined chiefly from galena (lead sulfide), often alongside zinc and silver. Major producers include China, Australia, and the United States.
Applications
Lead-acid car batteries
Radiation shielding
Solder and cable sheathing
Crystal glass and weights
Common compounds
- lead(II) oxide
- lead(II) chloride
- lead sulfate
Lead's symbol Pb comes from plumbum, Latin for lead — the Romans plumbed their cities with lead pipes, giving us the word ‘plumbing’.
Data source: IUPAC standard atomic weights 2021