Dioxygen difluorine (FOOF) is so reactive (unstable) it decays into O2 and F2 at about 4 % /day at -160 Celsius. It even reacts violently with ice.
Edit: Because everyone liked FOOF, get ready for tetraoxygen difluoride (FOOOOF) which is even more reactive. Apparently reacts explosively with elemental sulfur at -180 Celsius to form SF6.
Like fluorine. The chemical so dangerous that there’s an entire branch of science devoted to it.
More fluorine facts
Dioxygen difluorine (FOOF) is so reactive (unstable) it decays into O2 and F2 at about 4 % /day at -160 Celsius. It even reacts violently with ice.
Edit: Because everyone liked FOOF, get ready for tetraoxygen difluoride (FOOOOF) which is even more reactive. Apparently reacts explosively with elemental sulfur at -180 Celsius to form SF6.
FOOF