What does the term "isotope" refer to?

The term "isotope" refers to a variation of a given element, specifically differing in the number of neutrons in the atomic nucleus. All isotopes of an element have the same number of protons, which defines the element itself, but the varying number of neutrons results in different atomic masses. This means that isotopes can have differing physical and chemical properties, which can be important in applications such as radiometric dating, medical imaging, and nuclear energy.

Understanding isotopes is crucial in fields like nuclear physics and chemistry, as well as in the safe use of nuclear gauges in various industries. For instance, different isotopes of a radioactive material may have different half-lives, which affects how they are utilized in applications like analyzing material density or moisture content. In this context, the distinction between isotopes allows for the selection of specific isotopes for particular uses based on their stability and behavior.