>>13246370So when something dissolves in a solution, it doesn't disappear. The solvent molecules simple slip into the lattice of the solute. O2 is no different. The water molecules just orient themselves around it and trap it in the solution.
Its still O2. If it wasn't O2, life would literally not function.
If oxygen was a made into a free radical by dissolving, it would be reacting with all sorts of stuff in your blood and that has been proven to cause cancer (this is why "anti-oxidents" are good for you, they react with oxygen free radicals and make harmless waste, reducing the number of oxygen free radicals in your blood).
If oxygen changed is bonding mode, then it would change the oxidation state of the atoms, which would make respiration impossible, as that's how it works. At its core respiration is the reduction of oxidation from an oxidation state of 0 (O2) to and oxidation state of -2, by adding 2 electrons and 2 protons to make water (H2O). The energy from reduction fuels every process in your body. If you removed that energy when you dissolved O2 in water, you would die.