How do geologists use half-life to date rocks?

Answer by  Erynn (1651)

The half-life of any given material is a known quantity. If the rock contains a radio-active substance or a substance which decays in this way, by detecting how much it has lost we can tell how long it's been since it was made. Generally speaking geologists do not use half-life.

Answer by  Amber40 (24961)

All organic matter has a steady rate of decay. The loss of atoms or the "half life" of the material can be measured and used to calculate the approximate age of the material.

Answer by  Amber40 (24961)

All rocks contain certain periodical elements. These elements half distinct half-life periods. So by measuring this they can estimate the age of the rock.