# Half life equation radiometric dating

This is not true for zeroth- and second-order reactions.The half-life of a first-order reaction is independent of the concentration of the reactants.This becomes evident when we rearrange the integrated rate law for a first-order reaction (Equation 14.21) to produce the following equation: Figure $$\Page Index$$: The Half-Life of a First-Order Reaction.

Using Activity is usually measured in disintegrations per second (dps) or disintegrations per minute (dpm).

The parent-daughter ratio and half-lives elapsed hold no matter what minerals you are dealing with.

To determine the age, you need to know what the minerals are, and the half-life of the parent.

When the animal or plant dies, the carbon-14 nuclei in its tissues decay to nitrogen-14 nuclei by a radioactive process known as beta decay, which releases low-energy electrons (β particles) that can be detected and measured: $\ce \label$ The half-life for this reaction is 5700 ± 30 yr. Comparing the disintegrations per minute per gram of carbon from an archaeological sample with those from a recently living sample enables scientists to estimate the age of the artifact, as illustrated in Example 11.

Using this method implicitly assumes that the ratio in the atmosphere is constant, which is not strictly correct.