An atom of carbon (C) forms covalent bonds with two atoms of oxygen (O) to form carbon dioxide. How are the valence electrons of these atoms rearranged to form the bonds?

Question

Electrons are transferred from the carbon atom to the oxygen atoms.
Electrons are transferred from the oxygen atoms to the carbon atoms.
Many valence electrons are shared between the atoms.
A few valence electrons are shared between the atoms.

Answer 1

In the formation of carbon dioxide (CO₂), the correct description of how the valence electrons are rearranged to form covalent bonds is:

Many valence electrons are shared between the atoms.

In carbon dioxide, the carbon atom has four valence electrons and forms two double covalent bonds with two oxygen atoms. Each oxygen atom brings six valence electrons, and the sharing of electrons allows carbon to achieve a full outer shell (octet) while also allowing each oxygen to fill its valence shell. Therefore, many valence electrons are in fact shared in the formation of the bonds in carbon dioxide.