Radioactive Decay The Example of

Radioactive decay is a first-order, usually irreversible reaction with a rate given by 

Pagenkopf, Introduction to natural water chemistry, 1978. Reprinted by courtesy of Marcel Dekker, Inc. 

Natural carbon contains chiefly the stable isotopes C (-98.89%) and C (-1.10%) (Rosier and Lange 1972). Radioactive dating with C depends upon the fact that trace amounts of radioactive (-10 % of total C) are created from nitrogen gas in the upper atmosphere through the reaction 

The radioactivity of atmospheric C may, in fact, have varied from this disintegration rate by more than 10% in the last 6000 years (Henderson 1982). Age dating with C has been found useful for samples up to about 50,000 years old (Mason and Moore 1982). 

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