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'''Half-life''' is the time it takes for half of the original sample of a [[radioactive]] [[isotope]] to decay.<ref>Wile, Dr. Jay L. ''Exploring Creation With Physical Science''. Apologia Educational Ministries, Inc. 1999, 2000</ref>  Knowing these decay rates are important for dating, such as with [[carbon|carbon-14]].

'''Half-life''' is the time it takes for half of the original sample of a [[radioactive]] [[isotope]] to decay.<ref>Wile, Dr. Jay L. ''Exploring Creation With Physical Science''. Apologia Educational Ministries, Inc. 1999, 2000</ref> If the [[exponential decay]] of a radioisotope is expressed as <math>A = A_0 e^{-(t-t_0)/\tau}</math>, then the half-life is equal to <math>\tau</math> ln 2. Knowing these decay rates are important for dating, such as with [[carbon|carbon-14]].

==References==

==References==