Nuklida · stabil · alami

Timbal-206 (²⁰⁶Pb)

Timbal-206 (²⁰⁶Pb) adalah isotop stabil timbal dengan 82 proton dan 124 neutron (nomor massa 206). Kelimpahan alaminya [0.0190, 0.8673].

Data nuklida

Unsur
Timbal (Pb, Z = 82)
Nomor massa (A)
206
Proton (Z)
82
Neutron (N)
124
Massa atom
205.974465210 ± 0.000001228 u
Waktu paruh
Stable >2.5Zy
Mode peluruhan
Peluruhan alfa (α)
Inti anak
Raksa-202 (²⁰²Hg)
Kelimpahan alami
[0.0190, 0.8673]
Tahun penemuan
1927
Sumber data
IAEA Atomic Mass Data Center (NUBASE) and IUPAC CIAAW, via PubChem

Kegunaan isotop timbal

  • The study of lead isotopic compositions is used to model the distribution of pollution in water and on land (Fig. IUPAC.82.1). For example, in one study of Lake Härsvatten in Sweden, the isotope-amount ratio n(206Pb)/n(207Pb) measured at different sediment depths in different areas throughout the lake showed patterns of accumulation of lead pollution. In some cases, these patterns could be related to sediment distribution patterns. Another study used 210Pb (with a half-life of 22.6 years) dating methods to study the vertical accretion of sediments in canals and wetland areas in Louisiana over the last 80 to 100 years,. Three of the stable isotopes of lead (206Pb, 207Pb, and 208Pb) are produced by the radioactive decay of isotopes of uranium and thorium (238U, 235U, and 232Th, respectively) and are largely unaffected by environmental and metallurgical processes. Therefore, by examining various isotope-amount ratios of lead isotopes, it is possible to approximate the age of a material. It is also possible to use this information to trace the origins of an object or material,,,.
  • Different geographic regions may have characteristic terrestrial lead isotopic compositions because of variations in the ages and chemical composition of the rocks and minerals in the local environment. Therefore, lead produced at a particular location can have a unique lead isotopic composition and it is possible to trace the history and origins of pollutants by measuring the relative amounts of the four stable isotopes of lead (208Pb, 207Pb, 206Pb, and 204Pb) (Fig. IUPAC.82.2),. Using isotopic abundance data, the source of this toxic metal can be identified as it moves through air and water and eventually to living systems,. Scientists have analyzed lead in air pollution in California and found that it originated from Asia. Airborne particles from China have relatively higher amounts of 208Pb, which distinguishes the lead isotopic signature between airborne particles from Asia and North America. This knowledge could have implications in understanding the mixing of particles in the atmosphere and how pollutants are transported over vast distances,,,. Mapping the distribution of lead pollution by studying 204Pb, 206Pb, 207Pb and 208Pb also allows the identification of those human activities that contribute the highest amounts of lead to the environment,,. The measurement of the isotopic composition of lead in blood can help to determine the source of this toxic element in the body. Lead is stored in bones and teeth. If a person moves to a different geographical region, the isotopic composition of the lead in the teeth is maintained, recording their place of origin. Bone can store lead for long periods of time (about 20 years), and some skeletal lead may be older and have a different isotopic composition than other skeletal lead. These differences reflect exposure to lead of different origins. By studying the isotope-amount ratio n(206Pb)/n(204Pb) and n(207Pb)/n(206Pb) in bone and teeth, it is possible to determine someone’s place of origin. For example, isotopes of lead were analyzed in the teeth and bones of a human mummy, known as the “Iceman”, to help determine his place of origin,. 210Pb is a relatively short-lived radioactive isotope of lead that is constantly produced by the decay of 222Rn in the atmosphere. While living, humans naturally incorporate 210Pb from the environment into bones and tissues. The amount of 210Pb in the body reaches equilibrium such that the 210Pb ingested is in equilibrium with the 210Pb that decays. When a person dies, this incorporation of 210Pb ceases and the relative amount of this isotope in the body decreases. Therefore, measurement of the 210Pb activity in a corpse can help determine time of death,. Lead isotope-amount ratios n(206Pb)/n(204Pb), n(207Pb)/n(204Pb), and n(208Pb)/n(204Pb)) along with isotope-amount ratio of silver, n(107Ag)/n(109Ag), and isotope-amount ratio of copper n(65Cu)/n(63Cu) have been used to determine the origin of European coins and to investigate the flow of goods in the world market over time. Metals from Peru and Mexico and those from European mining have distinct isotopic signatures that enable the origin of the metal to be determined by examining the isotopic compositions of silver, copper, and lead in the coins. Abundant silver sources mined in Mexico and Peru in the 16 th century were used to mint coins, but were not a major influence in the European coin market until the 18 th century.
  • The three natural radioactive-decay chains beginning with 238U, 235U, and 232Th each have comparable half-lives that are much longer than the radioactive isotopes that follow until the production of stable isotopes of 206Pb, 207Pb, and 208Pb, respectively. Therefore, one can measure the relative amounts of the radiogenic isotopes of lead to determine the length of time that has elapsed since uranium and thorium atoms were incorporated into rocks and minerals. Typically, this method is used to date minerals that are tens of millions to billions of years old. The uranium-lead dating method was used to determine some of the first accurate ages of the Earth (about 4.55×109 years),,.

Isotop timbal lainnya

¹⁷⁸Pb, ¹⁷⁹Pb, ¹⁸⁰Pb, ¹⁸¹Pb, ¹⁸²Pb, ¹⁸³Pb, ¹⁸⁴Pb, ¹⁸⁵Pb, ¹⁸⁶Pb, ¹⁸⁷Pb, ¹⁸⁸Pb, ¹⁸⁹Pb, ¹⁹⁰Pb, ¹⁹¹Pb, ¹⁹²Pb, ¹⁹³Pb, ¹⁹⁴Pb, ¹⁹⁵Pb, ¹⁹⁶Pb, ¹⁹⁷Pb, ¹⁹⁸Pb, ¹⁹⁹Pb, ²⁰⁰Pb, ²⁰¹Pb, ²⁰²Pb, ²⁰³Pb, ²⁰⁴Pb, ²⁰⁵Pb, ²⁰⁷Pb, ²⁰⁸Pb, ²⁰⁹Pb, ²¹⁰Pb, ²¹¹Pb, ²¹²Pb, ²¹³Pb, ²¹⁴Pb, ²¹⁵Pb, ²¹⁶Pb, ²¹⁷Pb, ²¹⁸Pb, ²¹⁹Pb, ²²⁰Pb

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