What are the ions called that possess properties similar to halide ions and consist of two or more electronegative atoms,at least one of which is nitrogen?

In which one of the following pairs,both oxides are acidic?

The treatment of zinc with very dilute nitric acid produces

Identify the incorrect statement about $SiO_2$ (silica) from the following.

$A$ gas that cannot be collected over water is

$A$ compound $A$ is used in paints instead of salts of lead. Compound $A$ is obtained when a white compound $B$ is strongly heated. The compound $B$ is insoluble in water but dissolves in $NaOH$ solution,forming a solution of compound $C$. The compound $A$ on heating with coke gives a volatile metal $D$ and a gas $E$ which burns with a blue flame. Identify the possible species $D$ and $C$ respectively.