Choose the metalloid from the following elements:

The metals which can form amphoteric oxides with oxygen are:

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

Which of the above will form an acidic oxide?

Which of the following set of reactions will NOT occur?

I. ${\mathrm{MgSO}}_4\left(\mathrm{aq}\right) + \mathrm{Fe}\left(\mathrm{s}\right) \to {\mathrm{FeSO}}_4\left(\mathrm{aq}\right) + \mathrm{Mg}\left(\mathrm{s}\right)$

II. ${\mathrm{CuSO}}_4\left(\mathrm{aq}\right) + \mathrm{Fe}\left(\mathrm{s}\right) \to {\mathrm{FeSO}}_4\left(\mathrm{aq}\right) + \mathrm{Cu}\left(\mathrm{s}\right)$

III. ${\mathrm{MgSO}}_4\left(\mathrm{aq}\right) + \mathrm{Cu}\left(\mathrm{s}\right) \to {\mathrm{CuSO}}_4\left(\mathrm{aq}\right) + \mathrm{Mg}\left(\mathrm{s}\right)$

IV. ${\mathrm{CuSO}}_4\left(\mathrm{aq}\right) + \mathrm{Zn}\left(\mathrm{s}\right) \to {\mathrm{ZnSO}}_4\left(\mathrm{aq}\right) + \mathrm{Cu}\left(\mathrm{s}\right)$

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