What are elements with the same number of protons but differing numbers of neutrons called?

Elements with the same number of protons but differing numbers of neutrons are known as isotopes. The defining characteristic of an element is its number of protons, which determines its atomic number and, therefore, its identity as a specific element. However, the number of neutrons can vary in atoms of the same element, resulting in different isotopes.

For example, carbon has several isotopes, including carbon-12 (with 6 protons and 6 neutrons) and carbon-14 (with 6 protons and 8 neutrons). Both isotopes are still carbon because they have the same number of protons, but they differ in their neutron counts, which affects their mass and stability.

Recognizing isotopes is crucial in nuclear science and applications, such as in nuclear gauges, where the precise behavior and properties of different isotopes can influence measurement outcomes. This understanding plays a vital role in ensuring safety and accuracy in using nuclear materials.