Which of the following lead oxides is $Sindhur$?

Which is the correct sequence in the following properties? For the correct order mark $(T)$ and for the incorrect order mark $(F)$.
$(a)$ Lewis acidity order : $SiF_4 < SiCl_4 < SiBr_4 < SiI_4$
$(b)$ Melting point : $NH_3 > SbH_3 > AsH_3 > PH_3$
$(c)$ Boiling point : $NH_3 > SbH_3 > AsH_3 > PH_3$
$(d)$ Dipole moment order : $NH_3 > SbH_3 > AsH_3 > PH_3$

Which of the following compounds is the most explosive?

Identify the product obtained when excess chlorine reacts with ammonia.

Which pair of oxyacids of phosphorus contains $P-H$ bonds?

What are the products formed when ammonia reacts with excess chlorine?