List ofradioactive dating techniques
Some of the atoms eventually change from one element to another by a process called radioactive decay.
If there are a lot of atoms of the original element, called the parent element, the atoms decay to another element, called the daughter element, at a predictable rate.
Radiometric dating--the process of determining the age of rocks from the decay of their radioactive elements--has been in widespread use for over half a century.
There are over forty such techniques, each using a different radioactive element or a different way of measuring them.
Similarly, when all the atoms of the radioactive element are gone, the rock will no longer keep time (unless it receives a new batch of radioactive atoms).
The rate of loss of sand from from the top of an hourglass compared to exponential type of decay of radioactive elements.
In exponential decay the amount of material decreases by half during each half-life.The passage of time can be charted by the reduction in the number of parent atoms, and the increase in the number of daughter atoms.Radiometric dating can be compared to an hourglass.Most of the elements in nature are stable and do not change.However, some elements are not completely stable in their natural state.