Argon nuclides

If the amount of a radioactive nuclide in a rock sample is N, the sum of this amount plus the amount of its product nuclide is A/q. For argon dating, Nq is the sum of potassium-40 and argon-40 present in a sample of rock. Assuming that Ar gas escapes from molten rock but is trapped when the rock cools and solidifies, the lifetime obtained by substituting these values into Equation is the time since the rock solidified. Such analyses show that the oldest rock samples on Earth are 3.8 X 10 years old. 

The nuclide F can be introduced using a number of standard methods using fluorine, HF or fluoride anion. In contrast to normal chemistry, F2 (as a dilute mixture in argon or neon) is a convenient reagent in the PET context, being prepared directly by proton bombardment of 02 in argon, or deuteron bombardment of neon. An example of its use is the preparation of labelled 5-fluorouracil and its ribosides by direct electrophilic fluorination. ... 

Reedy RC, Nishiizumi K, Lai D, Arnold JR, Englert PAJ, Klein J, Middleton R, lull AJT, Donahue DJ (1994) Simulations of in situ cosmogenic nuclide production. Nucl Instr Meth Phys Res B92 297-300 Retme PR, Farley KA, Becker TA, Sharp WD (2001) Terrestrial cosmogenic argon. Earth Planet Sci Lett 188 435-440... 

Write the correct symbol, with both superscript and subscript, for each of the following. Use the fist of elements on the front inside cover as needed (a) the nuclide of hafnium that contains 107 neutrons (b) the isotope of argon with mass number 40 (c) an a particle (d) the isotope of indium with mass number 115 (e) the nuclide of silicon that has an equal number of protons and neutrons. 

Deduce the identity of the unknown daughter nuclide from the atomic number. Since the atomic number is 18, the daughter nuclide is argon (Ar). SKILLBUILDER 17.3 Writing Nuciear Equations for Positron Emission Write a nuclear equation for the positron emission of sodium-22. FOR MORE PRACTICE Example 17.8 Problems 63,64. 40, 40 A 0 19K ) isAr -1- +ie... 

The rate at which a sample of a radioactive nuclide decays is expressed in terms of half-life. This quantity is the time required for half of the atoms of a sample of a given nuclide to decay. For example, it takes 37.2 min for half of the nuclei of chlorine-38 to decay to argon-38. After 37.2 min, 0.50 g of a 1.0 g sample of chlorine-38 will remain, and there will be 0.50 g of argon-38. After two half-lives (74.4 min), the fraction of chlorine-38 that remains will be 1 of 1, or... 

Under this constraint, it is not possible to produce new superheavy nuclides at greater neutron excess by cold fusion, or by hot fusion with heavy-ion beams with lower atomic numbers than argon. This is because of the neutron richness of the overshoot isotopes, daughters of the multiple emission of relatively proton-rich a particles in the decays of the " Ca-induced evaporation residues. Nevertheless, both reaction types offer advantages in the production rates of the known isotopes of superheavy elements with Z = 106-108 that are of interest to the radiochemist. As examples Direct production of the long-lived hassium isotope Hs is possible in the cold-fusion irradiation of ° Pb with radioactive Fe. From Fig. 2, the cross... 

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