Respuesta :
Explanation:
Elements of group 18 are known as noble gases. The elements of this group are He, Ne, Ar, Kr, Xe, and Rn.
The electronic configuration of He is [tex]1s^{2}[/tex].
The electronic configuration of Ne is [tex]1s^{2}2s^{2}2p^{6}[/tex].
The electronic configuration of Ar is [tex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}[/tex].
The electronic configuration of Kr is [tex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}[/tex].
The electronic configuration of Xe is [tex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{6}[/tex]
The electronic configuration of Rn is [tex]1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{6}4f^{14}5d^{10}6s^{2}6p^{6}[/tex].
Thus, we can conclude that elements of group 18 have complete valence electron shells.
