Nitric oxide $(NO)$ is prepared by the action of dilute $HNO_3$ on which of the following metals?

Which of the following statements about phosphine $(PH_3)$ is/are correct?
$(a)$ It has a rotten egg-like smell.
$(b)$ In aqueous solution and in the presence of light,it yields red phosphorus and hydrogen.
$(c)$ It explodes with $Br_2$.
$(d)$ In its pure form,it is non-inflammable.

What is the number of oxygen atoms attached to each phosphorus atom in $P_4O_{10}$?

What happens when nitrogen dioxide $(NO_2)$ dissolves in water?

What is produced when $HNO_3$ reacts with $P_4O_{10}$?

The total number of paramagnetic gaseous products formed in all the following reactions $[A + B + C ]$:
$(A)\ NH_4 NO_3 \xrightarrow{\Delta} \text{Products}$
$(B)\ 3 NaNO_2 + 3 H_2 SO_4 \longrightarrow \text{Products}$
$(C)\ Pb(NO_3)_2 \xrightarrow{673 \ K} \text{Products}$