Answer: . Valence electrons are shared between oxygen atoms.
B.A double covalent bond is formed.
Explanation: Oxygen has atomic number 8 and is come under group 6.
Number of electrons in the outer most shell are known as Valence electrons of that atom.Oxygen has 6 Valence electrons and the valency of oxygen atom is 2. That's mean it can share 2 of its electrons to form a bond.
So , total valency in O2 molecule is 4. Each of the oxygen molecule share it's 2 electrons and form double covalent bonds.
By sharing two electrons by each of the oxygen atom it's outermost shell filled and it became stable oxygen molecule ( O2 ).
