Nitrogen Earth abundances

Heat-treated non-precious metal catalysts, synthesized from earth-abundant elements, are capable of catalyzing the ORR and efficiently generating electricity from fuels via a direct electrochemical conversion. Carbon-nitrogen precursors, supports, and in situ formed graphitized carbon play an important role in the catalyst performance. 

Oxygen is by far the most abundant element in cmstal rocks, composing 46.6% of the Hthosphere (4). In rock mineral stmctures, the predominant anion is, and water (H2O) itself is almost 90% oxygen by weight. The nonmetaUic elements fluorine, sulfur, carbon, nitrogen, chlorine, and phosphoms are present in lesser amounts in the Hthosphere. These elements aU play essential roles in life processes of plants and animals, and except for phosphoms and fluorine, they commonly occur in earth surface environments in gaseous form or as dissolved anions. 

The stratosphere contains, however, only small amounts--a few tenths of a ppb-of chlorine free radicals of natural origin. They are produced by the decomposition of methyl chloride, CH3Q. The nitrogen oxides (NO and NO2) are more abundant and are produced in the stratosphere by the decomposition of nitrous oxide, N2O. Both CH3CI and N2O are of biological origin these compounds, released at the Earth s surface, are sufficiently stable to reach the stratosphere in significant amounts. 

As evidenced by their low abundances, carbon compounds, water, and other volatiles such as nitrogen compounds were probably not significantly abundant constituents of the bulk of the solids that formed near the Earth. Many of the carriers of these volatiles condensed in cooler, more distant regions and were then scattered into the region where the Earth was forming. Eragments of comets and asteroids formed in the outer solar system still fall to Earth at a rate of 1 x 10 kg/yr and early in the... 

The thermodynamics of nitrogen chemistry helps explain why N2 is so abundant in the atmosphere, and yet the element remains inaccessible to most life forms. Table 14-4 shows that most of the abundant elements react with O2 spontaneously under standard conditions. This is why many of the elements occur in the Earth s crust as their oxides. However, N2 is resistant to oxidation, as shown by the positive A Gj for NO2. ... 

According to Table 14-4. chlorine is also resistant to oxidation. Unlike nitrogen, however, chlorine reacts spontaneously with metals to generate salts such as NaCl and MgCl2 Thus, among abundant elements on Earth, nitrogen is uniquely stable in... 

Because of their resistance to chemicai attack, nitrogen atoms are not iocked up in solid or liquid substances as are other eiements such as Si, Ai, Fe, and H. The most stabie form of the eiement nitrogen is a gaseous diatomic moiecuie with a very strong tripie bond. Therefore, the eiement nitrogen is concentrated in the Earth s gaseous atmosphere even though it is oniy a trace eiement in overaii abundance. 

Carbon is the I4th most abundant element, making up about 0.048% of the Earths crust. It is the sixth most abundant element in the universe, which contains 3.5 atoms of carbon for every atom of silicon. Carbon is a product of the cosmic nuclear process called fusion, through which helium nuclei are burned and fused together to form carbon atoms with the atomic number 12. Only five elements are more abundant in the universe than carbon hydrogen, helium, oxygen, neon, and nitrogen. 

ISOTOPES There are 19 isotopes of nitrogen, two of which are stable. The stable ones and their proportion to the natural abundance of nitrogen on Earth follow N-14 = 99.634% and N-15 = 0.366%. The other 17 isotopes are radioactive and man-made in nuclear reactors and have half-lives ranging from a few nanoseconds to 9.965 minutes. 

Fluorine is the 13th most abundant element on the Earth. It makes up about 0.06% of the Earths crust. Fluorine is widely distributed in many types of rocks and minerals, but never found in its pure form. Fluorine is as plentiful as nitrogen, chlorine, and copper, but less plentiful than aluminum or iron. 

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Schoenberg R, Zink S, Staubwasser M, von Blanckenburg F (2008) The stable Crisotope inventory of solid Earth reservoirs determined by double-spike MC-ICP-MS. Chem Geol 249 294-306 Schoenheimer R, Rittenberg D (1939) Studies in protein metabolism I, General considerations in the application of isotopes to the study of protein metabolism. The normal abundance of nitrogen isotopes in amino acids, J Biol Chem 127 285-290... 

When you burn anything in Lhe air, only about one-fifth of the air goes into chemical combination with what you are burning. The rest (except for a small fraction) does not enter into the process. Tt is a gas called nitrogen (X) — the most abundant free element on earth. 

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