What is the pressure, in kPa, exerted by a 0.43 mole sample of chlorine gas in a 15.6 L container at 19.5°C?

18 group.

The group 18 elements of periodic table never forms a ionic bond. Only this group is the exception where all the elements present in the group does not form any ionic bond. There are other elements also that do not form ionic bonds but not complete group. The noble atoms have complete outer shell so they can neither lose or gain any electron which form the group 18.