Which dating method uses the radioactive decay of elements to determine the age of an item?

The method that utilizes the radioactive decay of elements to determine the age of an item is radiometric dating. This technique relies on the principle of radioactive decay, where unstable isotopes of elements transform into stable isotopes at a predictable rate, known as their half-life. By measuring the ratio of the parent isotopes to the daughter isotopes within a sample, scientists can calculate the time that has elapsed since the organism or material was last alive or since the rock was formed.

Radiometric dating encompasses various specific methods, including carbon-14 dating, which is specifically used for organic materials and has a limit in terms of age. Other forms of radiometric dating use different isotopes, such as potassium-argon dating or uranium-lead dating, each suited for dating different types of materials over varying time scales.

Tree-ring dating and stratigraphic dating are based on different principles. Tree-ring dating, or dendrochronology, relies on the growth rings of trees, while stratigraphic dating involves analyzing sediment layers and their sequence to determine relative ages. However, neither method involves measuring radioactive decay.