Question

Give two reasons responsible for late discovery of noble gases

Answer 1

noble gases have fully filled outermost orbitals hence they were discovered late because first of all they were very chemically unreactive with other elements and secondly they are not ionisable easily because they have fully filled outermost orbitals

Answer 2

The common thing with the noble gases is that they have full outer shells, and don't react with anyelements. Noble gases werediscovered later than other elements , simply because they were extremely unreactive . Being intert they were difficult to isolate via chemical reactions