The most common version of an element is called its "most abundant isotope" or the "most common isotope." This is determined by the isotope's natural abundance—the proportion of that isotope found naturally compared to other isotopes of the same element. For example, Carbon-12 is the most abundant isotope of carbon, and Hydrogen-1 (protium) is the most common isotope of hydrogen.
In summary:
- The term that tells you the most common version of an element is its "most abundant isotope."
- This is identified by natural abundance, which can be inferred from the average atomic mass of the element since it reflects a weighted average of all isotopes present.
- Chemical elements have isotopes that differ in neutron number but share the same number of protons, and the isotope with the highest natural abundance is considered the most common version.
If the query refers to a general term, "most abundant isotope" or simply "common isotope" is the best answer.
