These initial elements consisted of a mix of stable and radioactive isotopes. In the case of iron, for example, the Earth ...

and the sum of the protons and neutrons gives the atomic mass, the number of neutrons defines the isotope of that element. For example, most carbon (≈ 99 %) has 6 protons and 6 neutrons and is written ...

The team is looking to improve ways of hunting for a radioactive isotope of iron called "iron-60" in lunar dust. Iron-60 has an atomic nucleus containing 26 protons and 34 neutrons, and its half ...

Isotopes are forms of a chemical element with specific properties. You can see the different chemical elements on the periodic table. Each element is distinguished by the number of protons, neutrons ...

Key fact Isotopes are forms of an element that have the same number of protons but different numbers of neutrons. There are three isotopes of hydrogen: hydrogen, deuterium (hydrogen-2) and tritium ...