Lead is soft and malleable, and has a relatively low melting point.
When freshly cut, lead is bluish-white; it tarnishes to a dull gray color when exposed to air.
Exceptions are mostly limited to organolead compounds.
Like the lighter members of the group, lead tends to bond with itself; it can form chains, rings and polyhedral structures.
The four stable isotopes of lead could theoretically undergo alpha decay to isotopes of mercury with a release of energy, but this has not been observed for any of them; their predicted half-lives range from 10 Three of the stable isotopes are found in three of the four major decay chains: lead-206, lead-207, and lead-208 are the final decay products of uranium-238, uranium-235, and thorium-232, respectively.
These decay chains are called the uranium series, the actinium series, and the thorium series.
Lead is easily extracted from its ores; prehistoric people in Western Asia knew of it.
Galena, a principal ore of lead, often bears silver, interest in which helped initiate widespread extraction and use of lead in ancient Rome.
Lead-208 has 126 neutrons, another magic number, which may explain why lead-208 is extraordinarily stable.
Lead production declined after the fall of Rome and did not reach comparable levels until the Industrial Revolution.
In 2014, annual global production of lead was about ten million tonnes, over half of which was from recycling.
Their isotopic concentration in a natural rock sample depends greatly on the presence of these three parent uranium and thorium isotopes.
For example, the relative abundance of lead-208 can range from 52% in normal samples to 90% in thorium ores; As time passes, the ratio of lead-206 and lead-207 to lead-204 increases, since the former two are supplemented by radioactive decay of heavier elements while the latter is not; this allows for lead–lead dating.
In lead, the inert pair effect increases the separation between its s- and p-orbitals, and the gap cannot be overcome by the energy that would be released by extra bonds following hybridization.