Khan Academy on a Stick : Radioactive decay

Khan Academy on a Stick

Chemistry

Types of Decay
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Alpha, Beta, Gamma Decay and Positron Emission
Half-Life
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Introduction to half-life
Exponential Decay Formula Proof (can skip, involves Calculus)
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Showing that N(t)=Ne^(-kt) describes the amount of a radioactive substance we have at time T. For students with background in Calculus. Not necessary for intro chemistry class.
Introduction to Exponential Decay
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Introduction to Exponential Decay
More Exponential Decay Examples
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A few more examples of exponential decay.