# Does radioactive dating work for gases

We are told that of all the radiometric dates that are measured, only a few percent are anomalous.

This gives us the impression that all but a small percentage of the dates computed by radiometric methods agree with the assumed ages of the rocks in which they are found, and that all of these various methods almost always give ages that agree with each other to within a few percentage points.   Furthermore, Parentium and Daughterium are so different in chemical properties that they don't otherwise occur together.

If there were such a pair of isotopes, radiometric dating would be very simple.

Radioactive elements "decay" (that is, change into other elements) by "half lives." If a half life is equal to one year, then one half of the radioactive element will have decayed in the first year after the mineral was formed; one half of the remainder will decay in the next year (leaving one-fourth remaining), and so forth.

The formula for the fraction remaining is one-half raised to the power given by the number of years divided by the half-life (in other words raised to a power equal to the number of half-lives).

But there are some questions that come to mind: Calculus students typically meet this problem somewhere in the second semester.