Which of the following material is not a semiconductor.
The correct statements from the following are :
(A) The decreasing order of atomic radii of group 13 elements is $$\mathrm{Tl}>\mathrm{In}>\mathrm{Ga}>\mathrm{Al}>\mathrm{B}$$.
(B) Down the group 13 electronegativity decreases from top to bottom.
(C) $$\mathrm{Al}$$ dissolves in dil. $$\mathrm{HCl}$$ and liberates $$\mathrm{H}_2$$ but conc. $$\mathrm{HNO}_3$$ renders $$\mathrm{Al}$$ passive by forming a protective oxide layer on the surface.
(D) All elements of group 13 exhibits highly stable +1 oxidation state.
(E) Hybridisation of $$\mathrm{Al}$$ in $$[\mathrm{Al}(\mathrm{H}_2 \mathrm{O})_6]^{3+}$$ ion is $$\mathrm{sp}^3 \mathrm{d}^2$$.
Choose the correct answer from the options given below :
The number of neutrons present in the more abundant isotope of boron is '$$x$$'. Amorphous boron upon heating with air forms a product, in which the oxidation state of boron is '$$y$$'. The value of $$x+y$$ is _________ .
Statement (I) : $\mathrm{SiO}_2$ and $\mathrm{GeO}_2$ are acidic while $\mathrm{SnO}$ and $\mathrm{PbO}$ are amphoteric in nature.
Statement (II) : Allotropic forms of carbon are due to property of catenation and $\mathrm{p} \pi-\mathrm{d} \pi$ bond formation.
In the light of the above statements, choose the most appropriate answer from the options given below :