Xenon's Isotopes 

Xenon has the second most stable isotopes (next to tin). There are a total of nine naturally existing isotopes. Xenon isotopes differ because they have a different number of neutrons, adding to the atomic mass of protons and neutrons. There are also over 18 radioactive isotopes of xenon -- radioactive isotopes are chemically unstable, therefore they are highly reactive. Radioactive isotopes essentially have the same characteristics as the element because they are still neutral atoms. Isotopes have the same amount of protons and electrons, so the structure of the atom hardly changes. Isotopes are also specified mainly by their mass number. For instance, Xe with an atomic number of 54 and 78 neutrons is labeled as Xe-132.