Physical Properties of Group 15 Elements

Which of the following is not an allotrope of phosphorous?

Which of the following atom have the highest melting points?

Why is $\mathrm{Bi}\left(\mathrm{V}\right)$ a stronger oxidant than $\mathrm{Sb}\left(\mathrm{V}\right)$ ?

How many of the following trends is(are) $CORRECT$with respect to the properties of hydrides of group $15$ elements?
$i.$ Basic strength:
${\mathrm{NH}}_3>{\mathrm{PH}}_3>{\mathrm{AsH}}_3>{\mathrm{SbH}}_3>{\mathrm{BiH}}_3$
$ii.$ Reducing character:
${\mathrm{NH}}_3<{\mathrm{PH}}_3<{\mathrm{AsH}}_3<{\mathrm{SbH}}_3<{\mathrm{BiH}}_3$
$iii.$ Thermal stability:
${\mathrm{NH}}_3>{\mathrm{PH}}_3>{\mathrm{AsH}}_3>{\mathrm{SbH}}_3>{\mathrm{BiH}}_3$
$iv.$ Boiling point:
${\mathrm{NH}}_3<{\mathrm{PH}}_3<{\mathrm{AsH}}_3<{\mathrm{SbH}}_3<{\mathrm{BiH}}_3$

Identify the incorrect statements about group 15
elements :

(A) Dinitrogen is a diatomic gas which acts like an
inert gas at room temperature.

(B) The common oxidation states of these
elements are –3, +3 and +5.

(C) Nitrogen has unique ability to form $\mathrm{p\pi }–\mathrm{p\pi }$
multiple bonds.

(D) The stability of +5 oxidation states increases
down the group.

(E) Nitrogen shows a maximum covalency of 6.
Choose the correct answer from the options given
below.

Given below are two statements:
Statement-I: Since fluorine is more electronegative than nitrogen, the net dipole moment of ${\mathrm{NF}}_3$ is greater than ${\mathrm{NH}}_3$.
Statement-II: In ${\mathrm{NH}}_3$, the orbital dipole due to lone pair and the dipole moment of $\mathrm{NH}$ bonds are in opposite direction, but in ${\mathrm{NF}}_3$ the orbital dipole due to lone pair and dipole moments of N-F bonds are in same direction.
In the light of the above statements. Choose the most appropriate from the options given below.

Given below are the two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R).

Assertion (A): There is a considerable increase in covalent radius from $N$ to $P$. However from $As$ to $Bi$ only a small increase in covalent radius is observed.

Reason (R): covalent and ionic radii in a particular oxidation state increases down the group.

In the light of the above statement, choose the most appropriate answer from the options given below:

The correct order of boiling point is:

Which of the following halides is most acidic?