Among the following halogens

$$\mathrm{F}_2, \mathrm{Cl}_2, \mathrm{Br}_2 \text { and } \mathrm{I}_2$$

Which can undergo disproportionation reactions?

Evaluate the following statements related to group 14 elements for their correctness.

(A) Covalent radius decreases down the group from $$\mathrm{C}$$ to $$\mathrm{Pb}$$ in a regular manner.

(B) Electronegativity decreases from $$\mathrm{C}$$ to $$\mathrm{Pb}$$ down the group gradually.

(C) Maximum covalance of $$\mathrm{C}$$ is 4 whereas other elements can expand their covalance due to presence of d orbitals.

(D) Heavier elements do not form $$\mathrm{p} \pi-\mathrm{p} \pi$$ bonds.

(E) Carbon can exhibit negative oxidation states.

Choose the correct answer from the options given below :

Given below are two statements :

Statement I : Gallium is used in the manufacturing of thermometers.

Statement II : A thermometer containing gallium is useful for measuring the freezing point $$(256 \mathrm{~K})$$ of brine solution.

In the light of the above statements, choose the correct answer from the options given below :

Which of the following material is not a semiconductor.