1 Divide the amount of the substance at one point in time by the amount remaining after a period of time. The formula for calculating half life is as follows: t 1/2 = t * ln(2)/ln
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1. Suppose you know the proportions of a substance at two points in time. Denote the difference between these two points in time with the letter "T. Denote the ratio of the smaller
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An awful lot of statistical manipulation would be involved in arriving at an answer, but you take a known number of atoms of the element and count how many decays occur over a set
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it takes 713 million years for half of the U235 to decay to lead207. halflives: 1 = 50% U235 . & 50% lead207. 2 = 25% U235 & 75% lead207. 3 = 12.5% U235 and 87.5% lead
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