Electronic configuration of element with atomic number $118$ will be $[R n] 5 f^{14} 6 d^{10} 7 s^{2} 7 p^{6}$. Since its electronic configuration in the outer most orbit $\left(n s^{2} n p^{6}\right)$ resemble with that of inert or noble gases, therefore it will be noble gas element. The inert gas radon has atomic number $86$. When we add $32$ electrons to it, we get the element with atomic number $118$. In seventh period, a maximum of $32$ electrons can be accommodated. Hence, element with atomic number $118$ is a noble gas.