Question

why was noble gas was discovered very late?

Answer 1

Hey, mate here is your answer》》

Because most elements were discovered through their reactivity with other elements, typically with oxygen, it was difficult for scientists to work with a substance that seemed to have little or no chemical properties based upon the lack of reactivity.

Hope this answer will help you..《《

Answer 2

I think that xenon all others like he, ne, ar,kr, rn is and all early discovered