Which one of the following is a semiconductor?

Which one of the following statements is not correct?

$P_2O_5$ is used extensively as a

Among the following oxides of $p$-block elements,the number of oxides having amphoteric nature is: $Cl_2O_7, CO, PbO_2, N_2O, NO, Al_2O_3, SiO_2, N_2O_5, SnO_2$

$SiCl_4$ on hydrolysis gives:

The most basic oxide of elements in group $14$ of the periodic table is