Most of the oxygen in the earth's atmosphere is in the form O2, but there is small portion of O3 (ozone). How come only some of the molecular oxygen is able to bond to another oxygen atom, and not all of it?

Arpeggionist

It is oxygen with a different number of neutrons, a different isotope. And you should thank your lucky stars for it. While O2 is beneficial for life on earth (and all multicellular organisms need it to live), o3 is actually toxic at ground level. Jul 18 06, 1:26 AM