Explain the following :

(i) Gallium has higher ionisation enthalpy than aluminium          (ii) Boron does not exist as B³⁺ ion          (iii) Aluminium forms [AlF₆] ^3– ion but boron does not form [BF₆] ^3– ion       (iv) PbX₂ is more stable than PbX_{4.               (v) Pb⁴⁺ acts as an oxidising agent but Sn²⁺ acts as a reducing agent.           (vi) Electron gain enthalpy of chlorine is more negative as compared to fluorine        (vii) Tl (NO3)3 acts as an oxidising agent.            (viii) Carbon shows catenation property but lead does not.          (ix) BF3 does not hydrolyse.}

_{(x) Why does the element silicon, not form a graphite like structure whereas carbon does.}

Assertion (A): Silicones are water repelling in nature.

Reason (R): Silicones are organosilicon polymers, which have (-R₂SiO-) as repeating unit.

(A) Both A and R are true and R is the correct explanation of A.

(B) Both A and R are true but R is not the correct explanation of A.

(C) Both A and R are not correct. 

(D) A is not correct but R is correct.

Assertion (A): If aluminium atoms replace a few silicon atoms in three dimensional network of silicon dioxide, the overall structure acquires a negative charge.

Reason (R): Aluminium is trivalent while silicon is tetravalent.

(A) Both A and R are true and R is the correct explanation of A.

(B) Both A and R are true but R is not the correct explanation of A.

(C) Both A and R are not correct.

(D) A is not correct but R is correct.

Match the species given in Column I with the hybridisation given in Column II.

Match the species given in Column I with properties given in Column II.

Match the species given in Column I with the properties mentioned in Column II.