While the number of protons defines the element (e.g., hydrogen, carbon, etc.) and the sum of the protons and neutrons gives the atomic mass, the number of neutrons defines the isotope of that element ...

This variation in the relative abundance of stable isotopes results from tiny mass differences that cause ... Deuterium (the heavy hydrogen isotope) has revolutionized stable isotope analysis ...

For this purpose, they must be separated using highly sophisticated techniques, such as mass spectrometry. While deuterium H-2, an isotope twice as heavy as hydrogen, is predominantly used in ...