8RB Group D 23-Sep-2018 Shift 1 Solved Paper

Helium(He), Neon (Ne), Argon (Ar) have filled outermost shells. Helium (He), neon (Ne), and argon (Ar), as group 18 elements, have outerelectron shells that are full or satisfy the octet rule. This makes them highly stable as single atoms. Because of their non-reactivity, they are called the inert gases or noble gases.