Stable isotopes can be used by measuring their amounts and proportions in samples, for example in water samples ... While deuterium H-2, an isotope twice as heavy as hydrogen, is predominantly used in ...

Deuterium, known as heavy hydrogen, is playing an increasingly important role, for example, in the development ... research is how to provide these isotopes in a highly pure form in an efficient ...

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 ...