Wow so you are talking about oxygen the atom (the smallest form of matter) versus oxygen the molecule (a group of atoms bonded together).
I think under your scenario the earth would explode in the biggest (and also last bomb the world will ever see).
Water is fascinating as a molecule. Truly unique in its chemistry and so essential for the formation of life. We write it water as H20 but it is really an H(OH) molecule. See atoms hate being alone..And oxygen in its outer shell has six free floating electrons (a part of the atom) At that distance from the nucleus an atom wants eight electrons to be happy.
So our oxygen friend needs two more friends. At first they find a single atom hydrogen and start to talking, once they know each other, maybe after a date or two, they bond and become H-O. This is called hydroxide and it has a negative charge.
The hyrdoxide finds another Hydrogen atom and you have water. What is neat is that little bit of negative charge caused by oxygen having a higher electronegativity creates little tiny magnets with a special chemical bond called covalent bonds make water hard to boil, do weird stuff as it freezes, and makes me and you possible.
Why the big bomb….well if you took out all the oxygen you would have massive amounts of hydrogen gas. See you can’t just remove oxygen from water. In your five seconds you would be do hydrolysis and being left with O2 (oxygen molecule) and H2 (hydrogen molecule). Hydrogen is sooo flammable…There would be no more fire (needs oxygen) but the pressure change caused by removing that much mass from the earth at once would in itself be catastrophic.
Along the way i am sure something would spark and light off the biggest Hindenburg the Milky Way has ever seen. …but wait there is no oxygen….can the hydrogen explode…
Just in the atmosphere alone there are 1.2 million billion metric tons of oxygen molecules. Removing this much mass would change earth’s orbit and magnetic fields….Remember there is no water all that mass is gone too as hydrolysis had to separate the hydrogen and oxygen. The oceans alone weigh 1,450,000,000,000,000,000 tons….All gone….
then the force of it all the oxygen coming back…the billions of billions of tiny bits of electricity around when new chemical bonds form…Still say the earth explodes.
.hmmm good question