Isotope (noun)

Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their atoms and hence have different atomic masses.

Origin:

1913, from german isotop, from greek isos "equal" + topos "place".

Examples:

1. Carbon-14 is a radioactive isotope that is used in dating ancient artifacts.
2. Scientists use isotopes to trace the movement of nutrients and pollutants in the environment.
3. Isotopes are used in medical treatment to diagnose and treat certain diseases.
4. The isotopes found in the samples suggested that the rock formed deep beneath the Earth's surface.
5. Heavier isotopes tend to be less stable than lighter isotopes.