Xenon Xenon is element number 54 on the periodic table of the elements. It has a mass of roughly 131 atomic mass units. There are 77 neutrons and 54 protons in the nucleus of the atom. The symbol for xenon is Xe and it belongs to the family of elements called the noble gases. It is called a noble gas because the valance shell of one atom contains a full shell. Xenon is one of the most stable elements on the table. The 54 electrons are arranged, so that there are 2 in the 1st shell, 8 in the 2nd, 18 in the 3rd, 18 in the 4th and lastly 8 in the 5th shell. The melting and boiling points of xenon are extremely low. They are -111°C and -107°C respectively. Xenon and most