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

Lead

Pb · Element 82 · Carbon group

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 8.7 W/m·K 24%

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 53%
Electron affinity 183.3 kJ/mol 88%

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.

Size, to scale

How big is a lead atom?

Radius 154 pm — that is 0.154 nm, so about 3247 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 is a heavy metal historically used in pipes and paint, now known to be toxic.

The discovery of lead

Ancient Discovery - Before Recorded History

🏺 Prehistoric Beginnings

Lead holds the distinction of being one of the earliest metals discovered and used by humanity, with evidence of lead working dating back to approximately 6500 BCE. Unlike many elements discovered in laboratories, lead's discovery predates written history, emerging from the practical needs of ancient civilizations.

The earliest known lead artifacts were found in Çatalhöyük, Turkey, dating to around 6500 BCE. These simple lead beads and trinkets suggest that ancient peoples discovered lead through the accidental smelting of galena (lead sulfide) in pottery kilns or cooking fires, where the relatively low melting point of lead (327°C) made it accessible with primitive technology.

🏛️ Ancient Civilizations

The ancient Egyptians were among the first to systematically use lead, employing it for cosmetics (kohl), weights, and waterproofing. Egyptian texts from 2000 BCE describe lead mining operations in the Eastern Desert, and lead artifacts are found in many pharaonic tombs, including thin lead sheets used in mummification processes.

Roman civilization elevated lead use to an industrial scale unprecedented in the ancient world. Romans called lead "plumbum" (hence our chemical symbol Pb), from which we derive words like "plumber" and "plumbing." They used lead extensively for:

  • Water pipes and aqueduct construction
  • Roofing and waterproofing materials
  • Coins and medallions
  • Cosmetics and medicinal preparations
  • Wine sweetening (a practice that may have contributed to the empire's decline)

Roman lead mines in Britain, Spain, and the Balkans produced thousands of tons annually. Lead ingots stamped with Roman imperial marks have been found throughout the former empire, demonstrating sophisticated production and trade networks.

⚗️ Medieval Alchemy

During the Medieval period, lead played a crucial role in alchemical theory. Alchemists associated lead with the planet Saturn and considered it the "base" metal from which all others originated. The famous alchemist Paracelsus (1493-1541) wrote extensively about lead's properties and its supposed transformation into gold.

Islamic scholars like Jabir ibn Hayyan (8th century) and Al-Razi (9th century) documented lead's chemical behavior, including its reaction with acids and its role in creating various compounds. Their systematic observations laid groundwork for later scientific understanding.

Medieval European monasteries became centers of lead working, using the metal for church windows, roofing, and illuminated manuscript decorations. The distinctive lead came used in stained glass windows represents a technological innovation that persists today.

🔬 Scientific Revolution

The transition from alchemical to scientific understanding of lead began during the 17th century. Robert Boyle (1627-1691) included lead in his systematic study of elements, recognizing it as a fundamental substance that could not be broken down further.

Antoine Lavoisier (1743-1794) definitively established lead as an element in his significant classification system, giving it the name we use today. His careful experiments with lead oxides helped establish the law of conservation of mass and the concept of chemical elements.

John Dalton included lead in his atomic theory (1803), assigning it an atomic weight and symbol. This marked lead's transformation from ancient metal to modern chemical element.

🏭 Industrial Age Expansion

The Industrial Revolution brought unprecedented demand for lead. The invention of the lead-acid battery by Gaston Planté in 1859 created an entirely new application that continues to dominate lead consumption today.

The discovery of tetraethyl lead as a gasoline additive by Thomas Midgley Jr. in 1921 dramatically expanded lead production, though this application was later recognized as a major environmental disaster and phased out globally.

Modern mining techniques developed in the 19th and 20th centuries, including froth flotation for ore processing, made large-scale lead production economically viable, transforming it from a precious metal to an industrial commodity.

🧬 Modern Understanding

The 20th century brought recognition of lead's toxicological properties, fundamentally changing how we view this ancient metal. Pioneering work by researchers like Clair Patterson, who studied lead contamination in the environment, led to the phase-out of leaded gasoline and paint.

Today's understanding encompasses lead's role in geochronology (uranium-lead dating), environmental science (pollution tracking), and nuclear physics (radiation shielding), showing how an ancient discovery continues to yield new scientific insights.

Applications

What lead is used for

Modern Industrial Applications

🔋 Battery Technology

Lead-acid batteries remain the dominant application, consuming about 85% of global lead production. These batteries power virtually all automotive starting systems, backup power for telecommunications, and emergency lighting systems. The lead plates serve as both positive electrode (lead dioxide, PbO₂) and negative electrode (metallic lead) in sulfuric acid electrolyte.

Advanced valve-regulated lead-acid (VRLA) batteries use absorbed glass mat technology for sealed operation, making them ideal for UPS systems, medical equipment, and marine applications. Modern designs achieve 10-15 year lifetimes with minimal maintenance.

Grid-scale energy storage increasingly relies on large lead-acid battery banks for renewable energy integration. Wind and solar farms use massive lead battery systems to store energy during peak production for release during demand spikes.

☢️ Radiation Shielding

Lead's high density (11.34 g/cm³) and high atomic number make it the gold standard for gamma radiation shielding. Medical X-ray rooms, nuclear power plants, and research facilities rely on lead-lined walls, doors, and windows to protect workers and the public.

Lead blankets and aprons protect medical professionals during X-ray procedures. Modern aprons use lead-equivalent materials like barium sulfate for lighter weight, but pure lead remains preferred for maximum protection.

Nuclear waste storage utilizes lead containers for transporting and storing radioactive materials. Lead's stability and radiation absorption make it irreplaceable for nuclear industry applications.

🏗️ Construction & Building

Roofing and weatherproofing applications take advantage of lead's corrosion resistance and malleability. Historic buildings worldwide feature lead roofing that has lasted centuries. Modern lead sheet is used for flashing, gutters, and weatherproofing in high-end construction.

Sound dampening utilizes lead's density for acoustic isolation. Recording studios, hospitals, and industrial facilities use lead-lined walls to reduce noise transmission. Lead-loaded vinyl sheets provide flexible sound barriers.

Pipe and cable sheathing protects underground utilities from corrosion and rodent damage. Lead's chemical stability makes it ideal for protecting electrical cables in harsh environments, though plastic alternatives are increasingly used.

⚗️ Chemical Processing

Sulfuric acid production relies on lead-lined equipment in the chamber process. Lead's resistance to sulfuric acid corrosion makes it essential for chemical manufacturing, though newer processes have reduced this application.

Pigments and ceramics still use lead compounds in specialized applications. Lead-based glazes provide unique colors and properties in artistic ceramics, though strictly regulated due to toxicity concerns.

Soldering alloys traditionally used lead-tin mixtures for electronics and plumbing. While lead-free alternatives are now standard for consumer electronics and potable water systems, lead solders remain important for high-reliability aerospace and military applications.

🎯 Specialized Applications

Ammunition manufacturing uses lead for bullets and shot due to its density, malleability, and low melting point. Lead bullets provide superior ballistic performance, though environmental concerns drive development of alternative materials for hunting applications.

Crystal glass (lead crystal) contains lead oxide to increase refractive index and density, creating brilliant optical properties prized in fine glassware. Lead content of 24% or higher defines true crystal glass.

Counterweights and ballast applications utilize lead's high density in elevators, cranes, and marine vessels. Lead's stability and ease of shaping make it ideal for precision balancing applications.

♻️ Recycling & Sustainability

Lead is one of the most recycled metals globally, with recycling rates exceeding 95% for automotive batteries. Secondary lead production from recycling now supplies about 60% of global lead demand, reducing environmental impact and conserving resources.

Everyday Applications

🚗 Automotive Batteries

Nearly every car, truck, and motorcycle depends on a lead-acid battery for starting and electrical systems. These 12-volt batteries contain lead plates in sulfuric acid, providing reliable power for decades. Even hybrid and electric vehicles often use smaller lead-acid batteries for accessories and backup systems.

Modern automotive batteries use calcium-lead alloys for improved performance and longer life, with some lasting 5-7 years under normal conditions.

🏥 Medical Protection

X-ray shielding in hospitals and dental offices uses lead aprons, gloves, and thyroid shields to protect patients and staff. Lead glass windows allow technicians to observe procedures while remaining protected from radiation.

Radiation therapy facilities use massive lead doors and walls (often several inches thick) to contain high-energy radiation beams used for cancer treatment.

🏠 Home & Building

Wheel weights for balancing car and truck tires traditionally used lead, though alternatives are increasingly common due to environmental concerns.

Fishing weights and sinkers rely on lead's density to sink lines quickly. Anglers use various lead weights from split shot to heavy pyramid sinkers, though some areas restrict lead tackle near waterfowl habitats.

Stained glass windows use lead "came" (H-shaped strips) to hold colored glass pieces together. This traditional technique, used for centuries in churches and decorative windows, creates flexible joints that accommodate building movement.

🔋 Backup Power

Uninterruptible Power Supplies (UPS) in offices, hospitals, and data centers use lead-acid batteries to provide emergency power during outages. These sealed batteries can operate for years without maintenance.

Emergency lighting systems in buildings rely on lead-acid batteries to power exit signs and emergency fixtures during power failures, as required by building codes.

Historical Uses (Many Now Restricted)

🎨 Paints & Pigments

Lead-based paint was widely used until the 1970s for its durability and vibrant colors. White lead (lead carbonate) provided excellent coverage and weather resistance. However, lead paint poses severe health risks, especially to children, and is now banned for residential use in most countries.

Many historic buildings still contain lead paint, requiring special procedures for renovation and removal to prevent lead dust exposure.

⛽ Gasoline Additive

Tetraethyl lead was added to gasoline from the 1920s-1980s as an anti-knock agent to improve engine performance. This practice released massive amounts of lead into the environment before being phased out due to health and environmental concerns.

The elimination of leaded gasoline is considered one of the greatest public health achievements of the 20th century, reducing childhood lead exposure dramatically.

🚰 Plumbing Systems

Lead pipes were common in water systems until the mid-20th century due to lead's malleability and corrosion resistance. Many older cities still have lead service lines connecting homes to water mains, though these are being systematically replaced.

Lead solder was used to join copper pipes until banned for potable water systems in the 1980s. Lead-free solder is now required for all drinking water plumbing.

Modern Safety Measures

While lead remains important for many applications, modern use emphasizes containment and recycling. Lead-acid batteries are recycled at rates exceeding 95%, and new applications must demonstrate that lead exposure is minimized throughout the product lifecycle.

Regulations now require lead-free alternatives for most consumer applications, with traditional lead uses limited to industrial applications where safer alternatives don't exist or where the risks can be properly managed.

Where it comes from

Natural occurrence

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

Geological Abundance

🌍 Crustal Distribution

Lead ranks as the 38th most abundant element in Earth's crust with an average concentration of about 14 parts per million. This makes it more common than silver, mercury, or cadmium, explaining why lead has been known and used since ancient times.

Lead concentrates in the continental crust rather than oceanic crust, with granitic rocks typically containing 15-20 ppm lead compared to basaltic rocks with only 3-8 ppm. This concentration pattern reflects lead's incompatible behavior during magmatic processes.

Most crustal lead exists in trace amounts dispersed through rock-forming minerals, but geological processes can concentrate it into economically viable ore deposits through hydrothermal and sedimentary processes.

⛏️ Primary Ore Minerals

Galena (PbS) is the most important lead ore mineral, accounting for over 90% of global lead production. This silvery-gray mineral forms distinctive cubic crystals and has been mined for over 5,000 years. Major galena deposits often contain silver as well, making them valuable for multiple metals.

Cerussite (PbCO₃) forms through weathering of galena deposits and appears as colorless to white crystals. While less common than galena, cerussite can be locally important, especially in arid regions where carbonate minerals are stable.

Anglesite (PbSO₄) also forms from galena weathering but is less economically important. It appears as yellow to colorless crystals and often occurs with cerussite in the oxidized zones of lead deposits.

Secondary minerals include pyromorphite, mimeteite, and vanadinite, which are lead phosphate, arsenate, and vanadate minerals respectively. These colorful minerals are prized by collectors but rarely constitute ore-grade concentrations.

🗺️ Major Mining Districts

China dominates global lead production with about 45% of world output, primarily from mines in Hunan, Yunnan, and Inner Mongolia provinces. The Huanzala mine in Peru and Red Dog mine in Alaska are among the world's largest individual lead producers.

Australia hosts significant lead deposits, particularly the Broken Hill district in New South Wales, which has been one of the world's most productive lead-silver-zinc mining areas for over 130 years. The Olympic Dam deposit in South Australia produces lead as a byproduct of copper-uranium mining.

Peru and Mexico are major producers in the Americas, with Peru's Cerro de Pasco region being historically significant for lead-zinc production. Mexico's Santa Eulalia district has been continuously mined since colonial times.

The Mississippi Valley Type (MVT) deposits in the central United States, including Missouri's Old Lead Belt and Southeast Missouri Lead District, have produced enormous quantities of lead over the past two centuries.

🔄 Geochemical Processes

Lead ore deposits form through several geological processes. Hydrothermal deposits are most common, where hot, metal-rich fluids precipitate lead sulfide in veins, replacements, and disseminated deposits. These fluids often originate from cooling magma chambers or metamorphic processes.

Sedimentary exhalative (SEDEX) deposits form when metal-rich brines discharge onto ancient seafloors, creating stratiform lead-zinc deposits. The giant Red Dog deposit in Alaska formed through this process.

Skarn deposits develop where intrusive igneous rocks contact limestone, creating high-temperature metamorphic zones where lead minerals can precipitate alongside other sulfides and oxides.

Volcanogenic massive sulfide (VMS) deposits form at ancient seafloor volcanic centers, though these typically contain more copper and zinc than lead.

🌊 Environmental Distribution

Natural background levels of lead in soils range from 10-50 ppm, though this has been significantly elevated in many areas due to human activities. Contaminated urban soils can contain hundreds to thousands of ppm lead from historical use of leaded gasoline, paint, and industrial activities.

Seawater contains very low lead concentrations (about 0.002 ppm) due to lead's tendency to bind to particles and settle to the seafloor. However, marine organisms can bioconcentrate lead, leading to elevated levels in some seafood.

Atmospheric lead has decreased dramatically since the phase-out of leaded gasoline, but industrial emissions, mining, and smelting continue to contribute to local air pollution. Lead particles can travel long distances in the atmosphere before depositing.

☢️ Isotopic Composition

Natural lead consists of four stable isotopes: Pb-208 (52.4%), Pb-206 (24.1%), Pb-207 (22.1%), and Pb-204 (1.4%). The first three are products of radioactive decay series (thorium, uranium, and actinium series respectively), while Pb-204 is primordial.

Lead isotope ratios vary geographically and provide valuable information for ore deposit genesis, environmental contamination sources, and archaeological provenance studies. This isotopic fingerprinting helps track pollution sources and understand ancient trade routes.

Handling

Safety

TOXIC HEAVY METAL - Cumulative Poison

Lead is a persistent neurotoxin that accumulates in the body over time. No safe level of exposure exists, especially for children.

🧠 Health Effects

Neurological damage: Lead preferentially affects the nervous system, causing reduced IQ, learning disabilities, attention problems, and behavioral issues in children. Adult exposure can cause memory loss, mood disorders, and peripheral neuropathy.

Developmental effects: Children under 6 years old are most vulnerable. Even low levels of exposure can cause permanent cognitive impairment, reduced academic performance, and increased risk of ADHD and antisocial behavior.

Cardiovascular effects: Chronic lead exposure increases blood pressure, heart disease risk, and stroke risk in adults. Lead interferes with cardiovascular function at the cellular level.

Reproductive toxicity: Lead exposure can cause fertility problems, pregnancy complications, premature birth, and low birth weight. It crosses the placenta and can harm developing fetuses.

Blood action level: CDC considers blood lead levels ≥5 μg/dL in children as elevated and requiring intervention, though many experts advocate for even lower thresholds.

🏠 Common Exposure Sources

Lead paint: Homes built before 1978 may contain lead paint. Renovation, repair, or painting can create dangerous lead dust. Professional abatement is required for safe removal.

Contaminated soil: Areas near old buildings, busy roads, or former industrial sites may have lead-contaminated soil from paint chips, leaded gasoline, or industrial activities.

Drinking water: Lead pipes, solder, or fixtures can leach lead into water, especially in older homes or during water chemistry changes. Even "lead-free" fixtures may contain up to 8% lead.

Occupational exposure: Construction workers, painters, battery manufacturers, firearms instructors, and auto mechanics face elevated lead exposure risks.

Consumer products: Some imported jewelry, toys, cosmetics, traditional medicines, and pottery may contain dangerous lead levels despite regulations.

🛡️ Protection Measures

Personal protection: Use NIOSH-approved respirators (P100 filters minimum) when working with lead. Wear disposable coveralls, gloves, and shoe covers. Never eat, drink, or smoke in lead work areas.

Workplace controls: Use engineering controls like local exhaust ventilation, wet methods to suppress dust, and HEPA filtration. Establish regulated areas with restricted access.

Hygiene practices: Wash hands and face before eating, drinking, or smoking. Shower and change clothes before going home. Use separate laundry for work clothes.

Home safety: Test homes built before 1978 for lead paint. Use EPA-certified contractors for renovation. Test water for lead, especially in older homes.

Medical surveillance: Workers with potential lead exposure need regular blood lead monitoring. Levels >40 μg/dL require medical removal from exposure.

🩺 Medical Management

Chelation therapy: For severe poisoning (blood levels >45 μg/dL in children, >80 μg/dL in adults), chelating agents like EDTA, DMSA, or BAL may be used to remove lead from the body.

Nutritional support: Adequate calcium, iron, and vitamin C can help reduce lead absorption. Iron deficiency increases lead absorption significantly.

Environmental remediation: The most important treatment is removing the source of exposure. Medical treatment without environmental cleanup is often ineffective.

Long-term monitoring: Lead poisoning effects can persist for years. Regular medical follow-up and educational support may be needed.

⚖️ Regulatory Standards

OSHA standards: Permissible exposure limit of 50 μg/m³ as 8-hour time-weighted average. Action level of 30 μg/m³ triggers enhanced safety requirements.

EPA regulations: Lead-based paint disclosure requirements, renovation and repair rules (RRP), and drinking water standards (action level 15 ppb).

International bans: Leaded gasoline is banned worldwide. Many countries restrict lead in paint, toys, and consumer products to very low levels.

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 holding 2, 8, 18, 32, 18, 4 electrons respectively. 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 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 — it occurs in a form usable without smelting, so no single person can be credited with its discovery. The name comes from 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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