How many different elements are in O2?

six

Explanation:

Professor of Chemistry, University of Minnesota, Minneapolis. Oxygen group element, also called chalcogen, any of the six chemical elements making up Group 16 (VIa) of the periodic classification—namely, oxygen (O), sulfur (S), selenium (Se), tellurium (Te), polonium (Po), and livermorium (Lv).

for 8 am not sure maybe yes?

for 9 if it is asking if the male is more or less it would be less

hope i even just a little : )