GEOL 212 Lecture Notes - Lecture 14: Gas Chromatography, Diffraction Grating, Mass Spectrometry
26 Dec 2017
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Document Summary
Atmospheres of the solid worlds: origin and composition. Sources of atmospheres: gasses present in the solar nebula (mostly hydrogen and helium, volatiles outgassed from planetary interiors. Oxidation and reduction: to a chemist, the term oxidation occurs when an atom loses electrons during a chemical reaction. Na + f -> na+f- sodium is oxidized by fluorine. Because the electron is being removed from the sodium by the fluorine, we call fluorine the oxidizing agent: reduction is the opposite - occurring when an element gains electrons during a chemical reaction. In the example above, fluorine is reduced by sodium. We refer to sodium as the reducing agent. It is common to refer to atmospheres as oxidizing or reducing depending on the whether their most common gasses act as oxidizing or reducing agents. The early earth is thought to have had a reducing atmosphere of n2and co2. Today there is an oxidizing atmosphere of n2 and o2.
