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 ...

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 ...

All three isotopes of hydrogen have identical chemical properties ... after the element and the mass number of its atoms. For example, carbon-12 is an isotope of carbon with a mass number of ...