The definition of an isotope is an element with similar chemical make-up and the same atomic number, but different atomic weights to another or others.(noun)
An example of an isotope is Carbon 12 to Carbon 13.
See isotope in Webster's New World College Dictionary
Origin: < iso- + Gr topos, place: see topic
See isotope in American Heritage Dictionary 4
Origin: + Greek topos, place (so called because the isotopes of a chemical element occupy the same position in the periodic table of elements).
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