82 Pb Lead 207.2
Post-transition metal p-block Period 6 Group 14

Lead

Pb · Element 82 · Post-transition metal

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Dense, soft and endlessly useful — and quietly responsible for centuries of chronic poisoning.

State at 20°C Solid
Atomic mass 207.2 u
Electron configuration[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²
81Tl All 118 83Bi

Structure

The lead atom

Not a diagram of dots on rings — a Monte-Carlo sample of the actual probability density |ψ|² for each occupied subshell. Drag to rotate. Blue and violet mark opposite signs of the wavefunction, which is what makes bonding possible.

Orbital cloud

Measured values

Property sheet

Every bar shows where lead sits among all 118 elements for that property.

Physical

Density 11.342 g/cm³ 69%
Melting point 600.6 K 31%
Boiling point 2022 K 44%
Specific heat 0.129 J/g·K
Thermal conductivity 35.3 W/m·K 56%

Atomic

Atomic radius 154 pm 48%
Covalent radius 146 pm
Van der Waals radius 202 pm

Electronic

Electronegativity 2.33 87%
Ionisation energy 715.9 kJ/mol 54%
Electron affinity 34.4 kJ/mol 31%

Occurrence

Abundance in crust 14 mg/kg 70%

Identity

SymbolPb
Atomic number82
Atomic mass207.2 u
CategoryPost-transition metal
Blockp
Crystal structureface-centered cubic
Oxidation states-4, +2, +4
DiscoveredAncient
Discovered byKnown since antiquity

Sources: IUPAC 2021 standard atomic weights · CRC Handbook of Chemistry and Physics · NIST. Values marked ~ are predicted rather than measured.

Same element, different neutrons

Isotopes of lead

All lead atoms have the same number of protons, 82, and differ only in their number of neutrons: those variants are its isotopes. The most common, Pb-208, has 126 neutrons and makes up 52.4% of natural lead.

Isotopes of lead found in nature, with their share of the natural element, and well-known radioactive ones
ISOTOPE Neutrons Natural Abundance Half-life Decay Mode
Pb-204 122 1.4% ≥1.4 × 10¹⁷ yrs α
Pb-206 124 24.1% Stable —
Pb-207 125 22.1% Stable —
Pb-208 most common 126 52.4% Stable —
Pb-210 128 — 22.20 yrs β⁻

The classroom shortcut, rounded atomic mass minus atomic number, gives 125 for lead, but the most common lead atom has 126 neutrons: the atomic mass, 207.2, is an average over all natural isotopes.

Decay modes

α
alpha decay
β⁻
beta-minus decay

Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.

Size, to scale

How big is a lead atom?

Radius 154 pm — that is 0.154 nm, so about 3.25 million of them side by side would span a millimetre.

Thermal range

Solid, liquid, gas — and when

Lead is liquid over a 1421 K window, from 601 K to 2022 K.

Where it sits

Position in the table

Lead sits in period 6, group 14. Everything in group 14 shares the same outer-electron count, which is why they behave so similarly.

Other post-transition metals

13Al 31Ga 49In 50Sn 81Tl 83Bi 84Po 113Nh 114Fl 115Mc 116Lv
All post-transition metals

The story

What lead is, and how we found it

Lead (Pb) is element 82, a soft, dense, bluish-gray metal in group 14, below tin. It melts at 327.46 °C (600.61 K), boils at 1,749 °C (2,022 K) and has a density of 11.342 g/cm³. Lead is easy to shape and resists corrosion, which made it useful for thousands of years, but it is a poison that harms almost every organ, especially the developing brain.

Atomic structure and isotopes

Lead has 82 electrons in six shells, arranged 2, 8, 18, 32, 18, 4, with the configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p². It usually forms compounds in the +2 oxidation state, and less often +4, as in the lead dioxide of car batteries.

Lead has four stable isotopes: lead-204, 206, 207 and 208. Three of them are end products of the radioactive decay of uranium and thorium, so the mix of isotopes varies from place to place, and it is used to date rocks. In 1956 Clair Patterson used lead isotopes to measure the age of Earth at about 4.55 billion years. Lead-208, with 82 protons and 126 neutrons, is the heaviest stable nucleus.

The discovery of lead

An ancient metal

Lead has been known since prehistory. It is easy to smelt from galena, and the oldest known metallic lead objects, from northern Mesopotamia and eastern Anatolia, are more than 7,500 years old. The Egyptians used lead compounds in cosmetics, and the Romans used the metal on a large scale for water pipes, roofing and containers.

Plumbum

The Latin name plumbum gives lead its symbol, Pb, and the words plumbing and plumber, from the Roman lead pipes. The English name lead comes from Old English.

Recognizing the danger

Lead poisoning was described in antiquity, but lead use kept growing. From the 1920s, lead added to gasoline spread lead around the world. Research by scientists such as Clair Patterson and Herbert Needleman showed the harm, and leaded gasoline, lead paint and lead pipes were phased out from the 1970s onward.

Applications

What lead is used for

Batteries

Lead-acid batteries account for most of the lead used today. They start almost every car, truck and motorcycle and provide backup power for telecommunications networks and data centers. They are also among the most recycled products: in many countries nearly all used batteries are collected, and more than half of the lead produced each year is recycled metal.

Radiation shielding and other uses

  • Shielding: lead sheets, bricks and aprons block X-rays and gamma rays in hospitals, dental offices and nuclear facilities.
  • Ammunition and weights: bullets, shot, fishing sinkers, wheel weights and ballast, although lead shot and sinkers are being restricted in many places to protect wildlife.
  • Construction: lead sheet for roofing and flashing, and sheathing for some power cables.
  • Glass and alloys: lead crystal glass, and lead alloys for bearings and some solders.

Uses that were phased out

Because of its toxicity, lead has been removed from gasoline (the last country stopped selling leaded gasoline for cars in 2021), from household paint, from new drinking water pipes and, in the EU and many other places, from most electronics solder.

In everyday life

  • Cars: the 12-volt starter battery of most cars is a lead-acid battery.
  • X-rays: the heavy apron you wear for a medical or dental X-ray contains lead or a lead-equivalent material.
  • Older homes: lead paint and lead water pipes can remain in buildings built before they were banned, and they are a major source of exposure.
  • Fishing and hunting: sinkers, jigs and shot.
  • Pencils: pencil "lead" is graphite mixed with clay and has never contained lead.

Where it comes from

Natural occurrence

14 mg/kg of Earth's crust · more abundant than 70% of elements

Abundance

Lead makes up about 14 parts per million of Earth's crust, which is unusually much for such a heavy element, because the decay of uranium and thorium keeps adding to it.

Ores

  • Galena (lead sulfide), the main ore, which often contains silver.
  • Cerussite (lead carbonate) and anglesite (lead sulfate), which form where galena weathers.

Production

Lead is mined mostly together with zinc and silver. China mines the most lead, followed by Australia, and Peru, the United States, Mexico, India and Russia also mine significant amounts (USGS). Recycling of batteries now supplies more lead than mining.

Handling

Safety

Health hazards

Lead is toxic, and the WHO states that there is no level of lead exposure known to be without harmful effects. In children it damages brain development, lowering IQ and affecting behavior and learning. In adults it raises blood pressure, harms the kidneys and can affect fertility and pregnancy. Lead builds up in bones and is released back into the blood over many years.

How exposure happens

People are exposed mainly by swallowing dust and soil contaminated by old lead paint or past gasoline emissions, by drinking water from lead pipes, through some traditional medicines, cosmetics and spices, and at work in battery recycling, smelting and renovation. Young children are most at risk, because they put things in their mouths and absorb lead more easily.

Safe handling

  • Wash your hands after handling lead objects, and do not eat, drink or smoke while working with lead.
  • Use wet methods and HEPA vacuums, not dry sanding, when removing old paint.
  • Melt or cast lead only with good ventilation, because fumes and dust are the main hazard.
  • Have children's blood lead tested if they may have been exposed.

Keep exploring

Use lead in the tools

Quick answers

Lead: common questions

What is lead?

Lead (symbol Pb) is element 82 on the periodic table, a post-transition metal in period 6, group 14. Dense, soft and endlessly useful — and quietly responsible for centuries of chronic poisoning. At room temperature it is a solid.

What is the electron configuration of lead?

Lead's ground-state electron configuration is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p², giving 6 occupied shells with the distribution 2, 8, 18, 32, 18, 4. Its outer shell holds 4 electrons, which is what sets its bonding behaviour.

What are the melting and boiling points of lead?

Lead melts at 600.6 K (327.5 °C) and boils at 2022 K (1748.9 °C).

What is the atomic mass of lead?

The standard atomic weight of lead is 207.2 u. That is a weighted average across its naturally occurring isotopes, which is why it is rarely a whole number.

How many neutrons does lead have?

The most common lead atom, Pb-208, has 126 neutrons: its mass number, 208, minus its atomic number, 82. It makes up 52.4% of natural lead. The classroom shortcut, rounded atomic mass (207.2) minus atomic number, gives 125 instead, because the atomic mass is an average over all natural isotopes of lead.

How dense is lead?

Lead has a density of 11.342 g/cm³. Water is 1.0 g/cm³, so a block of lead is about 11.3× heavier.

What is the electronegativity of lead?

Lead has a Pauling electronegativity of 2.33. The scale runs from 0.70 (francium, the least greedy for electrons) to 3.98 (fluorine, the most). Values in this middle band tend to form covalent rather than strongly ionic bonds.

Who discovered lead, and when?

Lead has been known since antiquity, long before anyone recorded its discovery, so no single person can be credited with it. Origin of the name: Anglo-Saxon lead; symbol from Latin plumbum.

How common is lead on Earth?

Lead makes up about 14 mg/kg of the Earth's crust — uncommon, but not rare.

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