Stable isotope. Relative atomic mass. Mole fraction 203 Tl Tl Thallium isotopes in Earth/planetary science

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Dwight Arron Malone
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$Stable isotope Relative atomic mass Mole fraction 203 Tl 202.972 345 0.2952 205 Tl 204.974 428 0.$ $biological properties, they commonly will be isotopically fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in$

1 Stable isotope Relative atomic mass Mole fraction 203 Tl Tl Thallium isotopes in Earth/planetary science Because molecules, atoms, and ions of the stable isotopes of thallium possess slightly different physical and chemical and biological properties, they commonly will be isotopically fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. There are substantial variations in the isotopic abundances of thallium in natural terrestrial materials (Figure 1). These variations are useful in investigating the origin of substances and studying environmental, hydrological, and geological processes [545].

2 The isotope-amount ratio n( 205 Tl)/n( 203 Tl) can be used to study how trace metals are transported and distributed in hydrothermal fluids [545]. The n( 205 Tl)/n( 203 Tl) ratio can be used to study the cycling, distribution and behavior of thallium in the marine environment [545]. Fig. 1: Variation in atomic weight with isotopic composition of selected thallium-bearing materials (modified from [1]). Thallium isotopes in medicine 201 Tl scintigraphy is used to detect coronary artery disease [546, 547]. 201 Tl imaging can be used for exercise perfusion tests of the myocardium (muscular tissue of the heart), which determines damage to the heart caused by a heart attack or heart disease (Figure 2) [546, 547].

Fig. 2: During exercise myocardium (muscular tissue of the heart) perfusion tests, a patient will exercise on a treadmill until they have reached their maximal exercise point (determined by heart

3 Fig. 2: During exercise myocardium (muscular tissue of the heart) perfusion tests, a patient will exercise on a treadmill until they have reached their maximal exercise point (determined by heart rate and age). Once they reach their maximal exercise point, a radionuclide (usually of thallium or technetium) is injected into the intravenous line in their arm, and the patient continues to exercise for a few more minutes. Once the radionuclide reaches the heart, the patient lies flat on a table and a gamma camera takes pictures of the heart for about 30 minutes. The areas of decreased blood flow or damaged tissue will be illuminated by the radionuclide. (Image source: National Heart Lung and Blood Institute, Diseases and Conditions Index, National Institutes of Health) [548]. Thallium isotopes used as a source of radioactive isotope(s) 203 Tl is used in the production of 201 Tl via the 203 Tl (p, 3 n) 201 Pb 201 Tl reaction. 205 Tl is being studied for use as an alternative target in the production of 201 Tl [546, 547].

4 Glossary atomic number (Z) The number of protons in the nucleus of an atom. atomic weight (relative mean atomic mass) the sum of the products of the relative atomic mass and the mole fraction of each stable and long-lived radioactive isotope of that element in the sample. The symbol of the atomic weight of element E is A r (E), and the symbol of the atomic weight of an atom (isotope) of element E having mass number A is A r ( A E). Because relative atomic masses are scaled (expressed relative) to one-twelfth the mass of a carbon-12 atom, atomic weights are dimensionless. [return] electron elementary particle of matter with a negative electric charge and a rest mass of about kg. element (chemical element) a species of atoms; all atoms with the same number of protons in the atomic nucleus. A pure chemical substance composed of atoms with the same number of protons in the atomic nucleus [703]. gamma camera (scintillation camera or Anger camera) instrument used to track the distribution in body tissue of radioactive isotopes (tracers) that emit gamma radiation (high energy photons), a technique known as scintigraphy. [return] gamma rays (gamma radiation) a stream of high-energy electromagnetic radiation given off by an atomic nucleus undergoing radioactive decay. The energies of gamma rays are higher than those of X-rays; thus, gamma rays have greater penetrating power. half-life (radioactive) the time interval that it takes for the total number of atoms of any radioactive isotope to decay and leave only one-half of the original number of atoms. intravenous (IV) administered into a vein. [return] isotope one of two or more species of atoms of a given element (having the same number of protons in the nucleus) with different atomic masses (different number of neutrons in the nucleus). The atom can either be a stable isotope or a radioactive isotope. isotope-amount ratio (r) amount (symbol n) of an isotope divided by the amount of another isotope of the chemical element in the same system [706]. [return] isotopic abundance (mole fraction or amount fraction) the amount (symbol n) of a given isotope (atom) in a sample divided by the total amount of all stable and long-lived radioactive isotopes of the chemical element in the sample. [return] isotopic fractionation (stable-isotope fractionation) preferential enrichment of one isotope of an element over another, owing to slight variations in their physical, chemical, or biological properties [706]. [return]

5 isotopic composition number and abundance of the isotopes of a chemical element that are naturally occurring [706]. [return] neutron an elementary particle with no net charge and a rest mass of about kg, slightly more than that of the proton. All atoms contain neutrons in their nucleus except for protium ( 1 H). perfusion tests using medical imaging to observe and record the passage of fluid through the lymphatic system or blood vessels to an organ or tissue. [return] proton an elementary particle having a rest mass of about kg, slightly less than that of a neutron, and a positive electric charge equal and opposite to that of the electron. The number of protons in the nucleus of an atom is the atomic number. radioactive decay the process by which unstable (or radioactive) isotopes lose energy by emitting alpha particles (helium nuclei), beta particles (positive or negative electrons), gamma radiation, neutrons or protons to reach a final stable energy state. radioactive isotope (radioisotope) an atom for which radioactive decay has been experimentally measured (also see half-life). radionuclide a nuclide that is radioactive [703]. [return] scintigraphy see gamma camera. [return] stable isotope an atom for which no radioactive decay has ever been experimentally measured. [return] tracer - substance used for tracking purposes. [return] X-rays electromagnetic radiation with a wavelength ranging from 0.01 to 10 nanometers shorter than those of UV rays and typically longer than those of gamma rays.

6 References 1. M. W. Wieser, and Coplen, T.B. Pure Applied Chemistry. 83, 359 (2011) T. S. I. Inc. Mercury Isotopes. Trace Sciences International Inc Feb T. S. H. Program. Mercury-Contaminated Fish- Is it Old or New Mercury? U.S. Geological Survey Feb M. Rehkamper, Frank, M., Hein, J.R., Porcelli, D., Halliday, A., Ingri, J., and Liebetrau, V. Earth and Planetary Science Letters. 197, 65 (2002) T. S. I. Inc. Thallium Isotopes. Trace Sciences International Inc Feb G. A. Beller, and Zaret, B.L. Circulation. 101, 1465 (2000) D. a. C. I. National Heart Lung and Blood Institute. Stress Testing. National Institutes of Health Feb I. U. o. P. a. A. Chemistry. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Blackwell Scientific Publications, Oxford (1997) Coplen. Rapid Communications in Mass Spectrometry. 25 (2011).

Stable isotope. Relative atomic mass

Stable isotope. Relative atomic mass Stable isotope Relative atomic mass Mole fraction 106 Cd 105.906 460 0.012 45 108 Cd 107.904 183 0.008 88 110 Cd 109.903 007 0.124 70 111 Cd 110.904 183 0.127 95 112 Cd 111.902 763 0.241 09 113 Cd 112.904