Lead plays a unique cosmological and geological role: it is the 稳定端点 of three of the four main natural radioactive decay chains. The stable isotopes of lead are the final products of the decay of uranium and thorium:
第四种稳定同位素\(^{204}\mathrm{Pb}\)并非放射成因，被称为“原生铅”，自太阳系形成之初便已存在。因此，如今地球上几乎所有的铅都是数十亿年来重元素放射性衰变的产物。
These decays make the uranium/thorium-lead isotopic system one of the 最强大且广泛使用的地质时钟. By measuring the ratios \(^{206}\mathrm{Pb}/^{238}\mathrm{U}\), \(^{207}\mathrm{Pb}/^{235}\mathrm{U}\), and \(^{207}\mathrm{Pb}/^{206}\mathrm{Pb}\) in a rock or mineral (such as zircon), geochronologists can accurately date events ranging from the formation of the solar system (4.567 Ga) to recent geological processes a few million years old. This method established the age of the Earth at about 4.54 billion years.
Lead isotopic ratios also serve as a 地球化学示踪剂. Since different geological reservoirs (mantle, continental crust, ore deposits) have distinct lead isotopic signatures, the origin of magmas, sediments, or even historical atmospheric pollution (the lead isotopic signatures of 1970s car exhaust differ from those of Roman mines) can be traced.
The cosmic abundance of lead is about 1.0×10⁻¹¹ that of hydrogen. It is synthesized in stars mainly by the s-过程 (slow neutron capture) in AGB stars, with a significant contribution from the r-过程 during supernovae. It is the heaviest stable element efficiently produced by the s-process, making it an abundance peak in the element spectrum. Its doubly magic nucleus (Z=82, complete proton shell) gives it exceptional stability.
The chemical symbol Pb comes from the Latin "plumbum" 的中文翻译是：铅, which also gave us the words "plumber" and "plumbing". In alchemy, lead was associated with the planet Saturn and symbolized heaviness, melancholy, and the raw material to be transmuted into gold (the goal of the "Great Work").
铅是人类最早加工的金属之一，与铜和金并列。其易于提取（仅需简单还原方铅矿PbS）的特性，以及可锻、易熔、耐腐蚀等性质，使其成为罗马人的首选材料。他们大规模将其用于：
Some historians suggest that 慢性铅中毒（铅中毒症） may have contributed to the decline of the Roman elite, affecting fertility and intellectual abilities.
The use of lead continued: cathedral roofs and stained glass, printing type, ammunition (bullets, shot), paint pigments (white lead for white, lead chromate for yellow), and weights. The Industrial Revolution greatly increased its production and uses, especially with the advent of 含铅涂料 and 含铅汽油 in the 20th century.
The main lead ore is 方铅矿 (PbS), a cubic metallic gray mineral often associated with sphalerite (ZnS) and silver. The main producing countries are 中国 (about half of world production), 澳大利亚, the 美国, 秘鲁, and 墨西哥. Annual mining production is about 450万吨. A significant portion (over 50%) now comes from 回收利用, especially from batteries.
铅的价格适中，通常随经济周期和汽车行业（用于电池）的需求波动。
铅（符号Pb，原子序数82）是一种后过渡元素，位于元素周期表第14族（碳族），与碳、硅、锗、锡同族。它是该族中最重且金属性最强的元素。其原子含有82个质子，通常有125至126个中子（对应同位素\(^{207}\mathrm{Pb}\)和\(^{208}\mathrm{Pb}\)），以及82个电子，电子排布为[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²。它有四个价电子（6s² 6p²）。
铅是一种蓝灰色、密度大、质地软、具有延展性的金属，熔点较低。
铅以面心立方（FCC）结构结晶。
Lead melts at 327.46 °C (600.61 K) and boils at 1749 °C (2022 K). Its wide temperature range in the solid state and ease of molding have historically facilitated its use.
铅是一种相当不活泼的金属，因其表面会形成一层由氧化物、碳酸盐或硫酸盐构成的保护层。它能抵抗大气腐蚀以及多种化学试剂的侵蚀，尤其是浓硫酸（用于电池中）。然而，铅会被硝酸和乙酸腐蚀。
Density: 11.34 g/cm³.
Melting point: 600.61 K (327.46 °C).
Boiling point: 2022 K (1749 °C).
Crystal structure: Face-centered cubic (FCC).
Electronic configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p².
Main oxidation states: +2 and +4.
| 同位素 / 符号 | 质子（Z） | 中子（N） | 原子质量（u） | 天然丰度 | 半衰期/稳定性 | 衰变/备注 |
|---|---|---|---|---|---|---|
| 铅-204 — \(^{204}\mathrm{Pb}\) | 82 | 122 | 203.973044 u | 约 1.4% | 稳定的 | 唯一稳定的非放射性同位素。"原始"同位素，用作地质年代学计算中的参考标准。 |
| 铅-206 — \(^{206}\mathrm{Pb}\) | 82 | 124 | 205.974465 u | ≈ 24.1% | 稳定 | \(^{238}\mathrm{U}\)衰变的稳定最终产物。主要放射性成因同位素。 |
| 铅-207 — \(^{207}\mathrm{Pb}\) | 82 | 125 | 206.975897 u | ≈ 22.1% | 稳定 | \(^{235}\mathrm{U}\)衰变的稳定最终产物。对\(^{207}\mathrm{Pb}/^{206}\mathrm{Pb}\)定年至关重要。 |
| 铅-208 — \(^{208}\mathrm{Pb}\) | 82 | 126 | 207.976652 u | ≈ 52.4% | 稳定的 | \(^{232}\mathrm{Th}\)衰变的稳定最终产物。已知最丰富且最重的稳定同位素（双幻核）。 |
注意：:
Electron shells: 电子如何围绕原子核组织.
铅有82个电子，分布在六个电子壳层中。其电子构型为 [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²，第六壳层（s² p²）有四个价电子，类似于碳或硅，但存在显著的相对论效应，使得6s²电子对非常惰性（"惰性电子对效应"）。这也可写作：K(2) L(8) M(18) N(32) O(18) P(4)，或完整形式：1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p²。
K壳层 (n=1): 2 electrons (1s²).
L壳层（n=2）: 8 electrons (2s² 2p⁶).
M壳层（n=3）: 18 electrons (3s² 3p⁶ 3d¹⁰).
N壳层（n=4）: 32 electrons (4s² 4p⁶ 4d¹⁰ 4f¹⁴).
O壳层（n=5）: 18 electrons (5s² 5p⁶ 5d¹⁰).
P壳层 (n=6): 4 electrons (6s² 6p²).
Lead has 4 价电子 (6s² 6p²). However, due to the inert pair effect, the +2 oxidation state (where only the 6p² pair is lost) is more stable and common than the +4 state (which would require losing the 6s² pair as well, which is stabilized).
这种化学性质与碳的化学性质形成对比，碳通常呈现+4价态，这体现了同一族元素性质的递变规律。
Freshly cut lead has a metallic luster that quickly tarnishes in air, forming a thin gray layer of 氧化铅(II) (PbO) and 碱式碳酸铅（2PbCO₃·Pb(OH)₂）, which protects it from further oxidation. When heated in air, it first forms litharge (PbO, yellow), then at higher temperatures, red lead (Pb₃O₄), a historical pigment.
1859年由加斯顿·普兰特发明，这是第一款可充电电池。其成功之处在于可靠性高、成本低廉，且具备输送强电流的高容量能力。
原理：
Negative electrode: Spongy lead (Pb).
Positive electrode: Lead dioxide (PbO₂).
Electrolyte: Sulfuric acid (H₂SO₄) at ~30%.
Discharge reaction: Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O
应用无处不在：车辆启动（SLI）、备用电源（UPS）、电动汽车（牵引）、离网光伏系统。这些电池的回收效率非常高（发达国家超过99%）。
The high density and atomic number of lead make it an 理想护盾 against ionizing radiation. It effectively absorbs X-rays and gamma rays. It is used in the form of:
Lead is a 累积毒素 with no known biological function. It interferes with many enzymatic processes by substituting for other essential metal ions, particularly 钙（Ca²⁺）和锌（Zn²⁺）. Its main targets are:
There is no demonstrated 安全阈值, especially for children. The WHO considers a blood lead level (BLL) above 5 µg/dL in children to be concerning. Health authorities recommend the "precautionary principle": reduce exposure as much as possible.
排放到大气中的铅会沉积在土壤和水体中。在大多数土壤中，铅的迁移性较弱，并在表层积累。在酸性环境中，铅的迁移性增强，可能污染地下水。铅不会降解，其持久性可达数千年。
Notable cases include the city of 赞比亚的卡布韦 (pollution from the old lead mine), the 美国西达拉斯社区 (former smelter), and the widespread contamination from leaded gasoline, whose fallout is measurable in polar ice and lake sediments worldwide.
This is a model of the 循环经济. Used batteries are collected, crushed, and the components are separated. The lead is remelted and refined to produce secondary lead of identical quality to primary lead. This process uses up to 80% less energy than mining.
鉴于其已被证实的毒性，已实施了严格的国际法规：
修复过程复杂且成本高昂。方法包括挖掘并掩埋受污染土壤、稳定化/固化处理（将铅锁定在基质中），或植物修复（利用某些蕨类等富集植物）。
铅展示了一种有用但危险材料的悖论。目标是：
铅的历史是一个强有力的警示，提醒我们在技术大规模推广之前，必须评估其长期影响。
原子的各种形态：从古代直觉到量子力学 
