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 ...

Uranium (chemical symbol U) is a naturally occurring radioactive element ... In its natural state, it consists of three isotopes (U-234, U-235 and U-238). Other isotopes that cannot be found in ...

This Section implements all activities of the IAEA's Water Resources Programme, which promotes and transfers know-how on the use of isotope hydrology as an effective tool for water resources ...

Experts debated the meaning of these violent-looking skulls from northern Spain for years, “but these hypotheses have not ...