$A$ red solid is insoluble in water. However,it becomes soluble if some $KI$ is added to water. Heating the red solid in a test tube results in the liberation of violet-coloured fumes and droplets of a metal appear on the cooler parts of the test tube. The red solid is:

Which statement is wrong?

The silicate having one monovalent corner oxygen atom in each $SiO_4$ tetrahedron unit is:

The element $X$ on reaction with conc. $HNO_3$ forms two acidic oxides $A$ and $B$ of different shapes. Element $Z$ on reaction with conc. $H_2SO_4$ forms two acidic oxides $A$ and $D$ of different shapes. What are $X$ and $Z$?

Evaluate the following statements related to group $14$ elements for their correctness.
$(A)$ Covalent radius decreases down the group from $C$ to $Pb$ in a regular manner.
$(B)$ Electronegativity decreases from $C$ to $Pb$ down the group gradually.
$(C)$ Maximum covalence of $C$ is $4$ whereas other elements can expand their covalence due to presence of $d$ orbitals.
$(D)$ Heavier elements do not form $p\pi-p\pi$ bonds.
$(E)$ Carbon can exhibit negative oxidation states.
Choose the correct answer from the options given below:

In the carbon family,elements other than carbon do not form $p\pi - p\pi$ bonds because their atomic radii are very ........