In qualitative test for identification of presence of phosphorous, the compound is heated with an oxidising agent. Which is further treated with nitric acid and ammonium molybdate respectively. The yellow coloured precipitate obtained is :

Give below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: The stability order of +1 oxidation state of $$\mathrm{Ga}$$, In and $$\mathrm{Tl}$$ is Ga < In < Tl.

Reason R: The inert pair effect stabilizes the lower oxidation state down the group.

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

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 :