Thecomponds of noble gases were discovered late 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 on the lack of reactivity.

not all noble gases combine with oxygen and fluorine only.the heavier noble gases like Xe , etc will react with fluorine and oxygen.noble gases form compounds with oxygen and fluorine because they are the most electronegative elements.they can also ionise the noble gases