what is isotope

Isotopes are different versions of an element that have the same number of protons but different numbers of neutrons in their nuclei. They share almost the same chemical properties, but their nuclear properties vary, making some invaluable for mankind, while others have no practical value. For example, carbon has six protons and is atomic number 6. Carbon occurs naturally in three isotopes: carbon 12, which has 6 neutrons (plus 6 protons equals 12), carbon 13, which has 7 neutrons (plus 6 protons equals 13), and carbon 14, which has 8 neutrons (plus 6 protons equals 14) . Isotope analysis is the determination of isotopic signature, the relative abundances of isotopes of a given element in a particular sample. Isotope analysis is frequently done by isotope ratio mass spectrometry. Isotopes have unique properties, and these properties make them useful in diagnostics and treatment applications. They are important in nuclear medicine, oil and gas exploration, basic research, and national security.