SO2, or sulfur dioxide, primarily exhibits covalent bonding. This is because the bond formed between the sulfur (S) atom and the oxygen (O) atoms involves the sharing of electrons, rather than the transfer of electrons that characterizes ionic bonds.
In SO2, sulfur has six valence electrons, while each oxygen atom has six as well. To achieve a full outer shell and reach stability, sulfur shares one electron with each of the two oxygen atoms. This electron sharing leads to a covalent bond, which is typical for nonmetals like sulfur and oxygen.
Additionally, SO2 has a bent molecular geometry due to the presence of a lone pair of electrons on the sulfur atom, which further supports its covalent nature. The difference in electronegativity between sulfur and oxygen is not enough to result in a complete transfer of electrons, reinforcing the covalent character of the bonds in sulfur dioxide.