Nonmetals acts as agents. (oxidising/ reducing)

An element $\mathrm{X}$ forms two oxides $\mathrm{XO}$ and ${\mathrm{XO}}_2$. The oxide $\mathrm{XO}$ is neutral but ${\mathrm{XO}}_2$ is acidic in nature.The element $\mathrm{X}$ is most likely to be 

Four elements W, X, Y, and Z have atomic numbers 12,18, 4, and 16:

Which of the above will form an acidic oxide?

Classify the following oxides into three types and name the types.

$\mathrm{CaO}, \mathrm{MgO}, {\mathrm{CO}}_2, {\mathrm{SO}}_3, {\mathrm{Na}}_2\mathrm{O}, \mathrm{ZnO}, {\mathrm{AI}}_2{\mathrm{O}}_3, {\mathrm{Fe}}_2{\mathrm{O}}_3$