For p-block elements (like Group 16), the non-metal oxides are typically acidic, and the oxides where the element is in an intermediate oxidation state (like $+4$ for $\text{SO}_2$ and $\text{SeO}_2$) can act as both oxidizing and reducing agents. The physical state of oxides often changes down a group due to size and polarizability (e.g., $\text{SO}_2$ is a gas, $\text{SeO}_2$ is a solid).