Oxygen is a pure element. It's element 8 on the Periodic Table. 8 protons, 8 electrons, 8 neutrons. Atomic Mass is about 16 amu (atomic mass units)
not your business
Yes
No, it is not.
Yes.
They don't need oxgyen but they need c2o which we exert and oxgyen is what plants exert
No, it is an element.
helium
hydrogen and oxgyen
gas
8
20.94 % in our atmosphere.
oxgyen