Metium, also known as eka-radon or element 118, is the name for the transactinide element having the atomic number 118 and element symbol Mu. On the periodic table of the elements, it is a p-block element and the last one of the 7th period. The radioactive Metium atom is very unstable. Although Metium is a member of the noble gas group, it has a higher chemical reactivity than some elements outside this group. Furthermore, it is known that it is a gas under normal conditions.