Ionic radius (in $\mathring{A}$) of $As^{3+}$,$Sb^{3+}$ and $Bi^{3+}$ follow the order:

When ammonia is passed over heated $CuO$,it is oxidised to

On reaction with $Cl_2$,phosphorus forms two types of halides $A$ and $B$. Halide $A$ is a yellowish-white powder,while halide $B$ is a colourless oily liquid. Identify $A$ and $B$ and write the formulas of their hydrolysis products.

Two oxides of nitrogen,$NO$ and $NO_2$ are allowed to react together at $243 \ K$ to form a coloured compound of nitrogen $(X)$. When compound $(X)$ reacts with water,it yields another compound of nitrogen $(Y)$. The shape of the anion of $(Y)$ molecule is:

Which element of group $-15$ forms the most basic hydride with hydrogen?

Which of the following is a metalloid?