Isotópum

Isotópum refers to isotopes, the variant forms of a chemical element that share the same number of protons but differ in the number of neutrons. Consequently, isotopes have the same atomic number but different mass numbers. Because chemical properties are largely governed by electron configuration, isotopes of the same element behave very similarly chemically, while their nuclear properties—such as stability and decay—can differ substantially.

In nature, elements can have multiple isotopes, some stable and others radioactive. The existence of stable isotopes provides the basis for precise measurements, while radioactive isotopes decay over characteristic timescales described by half-lives. The mass difference between isotopes leads to slight variations in physical properties, such as atomic mass, vibrational frequencies, and reaction rates, which can be exploited in scientific measurements.

Common examples include carbon with C-12, C-13, and C-14; hydrogen with protium (H-1), deuterium (H-2), and tritium (H-3); and chlorine with Cl-35 and Cl-37. The nearly identical chemistry of isotopes makes them useful as tracers in chemistry and biology and as tools in environmental and medical applications.

Applications span radiometric dating (for example, carbon-14 dating), medical diagnostics and therapy (such as technetium-99m and fluorine-18 in imaging), and industrial tracing. Isotope separation and enrichment techniques, notably mass spectrometry and various physical or chemical methods, allow the isolation and study of specific isotopes for research and practical use.

Historically, the concept of isotopes emerged in the early 20th century, with foundational work by scientists such as Frederick Soddy and later confirmation through mass spectrometry experiments.