Superphosphate of lime is

Phosphine is prepared by the reaction of $P_4$ with which of the following?

When hot and concentrated nitric acid reacts with copper,the gas obtained is:

Phosphine is produced by adding water to

$A$ group $15$ element forms $d \pi - d \pi$ bond with transition metals. It also forms a hydride,which is the strongest base among the hydrides of other group members that form $d \pi - d \pi$ bonds. The atomic number of the element is $.......$

Which statement is false?