What best explains how two oxygen atoms, each with six valence electrons, can bond with each other?

Question

One atom can lose two electrons so that the other atom can gain them and have eight valence electrons.
One atom can lose four electrons to the environment so that a total of eight valence electrons remains.
Each atom can share two electrons with the other so that each atom has eight valence electrons.
Each atom can lose two electrons so that there is a total of eight valence electrons between the atoms.

Answer 1

The best explanation of how two oxygen atoms, each with six valence electrons, can bond with each other is:

Each atom can share two electrons with the other so that each atom has eight valence electrons.

This describes covalent bonding, where the two oxygen atoms share a pair of electrons, allowing both to achieve a full octet (eight valence electrons) and thus stabilize their electronic configuration. In the case of oxygen, this results in a double bond between the two atoms.