Among the members of $V$ $A$ group ($N$,$P$,$As$,$Sb$,and $Bi$),which of the following properties shows an increase as we go down from nitrogen to bismuth?

The minimum temperature required for a non-catalytic reaction between $N_2$ and $O_2$ is (in $K$)

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 molecules has the highest number of $P-H$ bonds?

Which of the following is metaphosphoric acid?

In $P_4$ (tetrahedral) molecule: