## The decay rate and therefore the half-life are fixed characteristics of a nuclide. They don't change at all. That's the first axiom of radiometric dating techniques:

Unstable radioactive isotopes of elements, such as Uranium-235, decay at constant, known rates over time (its half-life, which is over 700 million years).

## Absolute Dating

## Methods used to determine age of fossils: a) relative dating, b) radiometric dating, which is Vocabulary: decay of material, half-life of a radioactive element.

15 Apr 2016 Students will discover that each radioactive isotope has a specific half-life. Students will develop mathematical model for the radioactive decay

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