Nitrogen relative isotopic abundance

Figure 2. Nitrogen isotope abundances in solar system materials upper scale gives absolute ratios lower scale gives relative to the terrestrial AIR standard. Heavy bars show observed ranges light bars show measurement...

Comet accretion models. Noble gases, as well as water, carbon, and nitrogen, could have been supplied to the inner planets by accretion of volatile-rich icy comets scattered inward from the outer solar system. Although noble gas isotopic distributions in comets are unknown, solar isotopic compositions would be expected in cometary gases acquired from the nebula. There is experimental evidence that the relative elemental abundances of heavier species (Xe, Kr, and Ar) trapped in water ice at plausible comet formation temperatures ( 30 K) approximately reflect those of the ambient gas phase, and trapped noble gas abundances per gram of water are substantial (Bar-Nun et al. 1985 Owen et al. 

The natural variations in isotopic abundances can be large, depending on the relative elemental mass differences hydrogen (100%) > oxygen (12.5%) > carbon (8.3%) > nitrogen (7.1%), see also Table 2.48 (Rossmann, 2001 Rosman and Taylor,... 

Nitrogen has two stable isotopes N (relative atomic mass 14.003 07, abundance 99.634%) and (15.000 11, 0.366%) their relative abundance (272 1) is almost invariant in terrestrial sources and corresponds to an atomic weight of 14.00674(7). Both isotopes have a nuclear spin and can be used in nmr experiments. though... 

The most abundant isotope is which constitutes almost 99% of the carbon in nature. About 1% of the carbon atoms are There are, however, small but significant differences in the relative abundance of the carbon isotopes in different carbon reservoirs. The differences in isotopic composition have proven to be an important tool when estimating exchange rates between the reservoirs. Isotopic variations are caused by fractionation processes (discussed below) and, for C, radioactive decay. Formation of takes place only in the upper atmosphere where neutrons generated by cosmic radiation react with nitrogen ... 

Table 14.1 Relative abundances of the stable isotopes of hydrogen, carbon, nitrogen, oxygen and sulfur (Hoefs 1996 Schoeller 1999)...

Nielsen SG, Rehkamper M, Brandon AD, Norman MD, Turner S, O Reilly SY (2007) Thallium isotopes in Iceland and Azores lavas - Implications for the role of altered crust and mantle geochemistry. Earth Planet Sd Lett 264 332-345 Nier AO (1950) A redetermination of the relative abundances of the isotopes of carbon, nitrogen, oxygen, argon and potassium. Phys Rev 77 789... 

The two isotopes N (7 = 1) and N (7 = 1/2) both have only small values of S and thus belong to the class of insensitive nuclides. Although the electric quadrupole moment of N is relatively small and the signals are therefore not very greatly broadened, the overwhelming majority of nitrogen NMR studies are now performed on N using natural abundance samples, despite the difficulties involved. The spread of chemical shifts for... 

Nier, A. O. (1950) A redetermination of the relative abundances of the isotopes of carbon, nitrogen, oxygen, argon, and potassium. Physical Review, 77, 793-798. 

A neutral organic compound, composed of the most abundant isotopes of the el erne tils present, with an even number of nitrogen atoms 111 List have an even relative molecular mass, but a compound with an odd number of nitrogen atoms must have an odd relative molecular mass. 

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