Question

why does inert gases placed in zero group

Answer 1

Elements placed in the periodic table on the basis of their valency and outer most shell electrons present. Na and K is with the outermost shell having one electron and the valency is also one.

Inert gas elements have their outer most shell completed or full. So they have no tendency to enter into any chemical reaction by giving or receiving electrons.

Answer 2

here is the answer......................................

Inert gas elements have their outer most shell completed or full. So they have no tendency to enter into any chemical reaction by giving or receiving electrons. Hence, inert gases are chemically inert and placed in zero group (Group-viii) in the periodic table. Inert gases with zero valency.