Question

Which of the following elements of group V-A does not show allotropy?
A.$N$
B.$Bi$
C.$P$
D.$As$

Answer 1

If the chemical elements have two or more different physical forms, that type of chemical element is known as allotropy. Here, in crystalline solids, there is a difference in the arrangement of atoms or the molecules containing different numbers of atoms and the example is, diamond and graphite are the allotropes of carbon atoms and these occur in solid state.

Complete answer:
The nitrogen is a chemical element which is occupied in group five in the periodic table. And the solid nitrogen contains allotrope. And dinitrogen is the allotrope of nitrogen. Hence, option (A) is incorrect.
Among the given options, bismuth does not have any allotropes. Whereas, remaining all elements which are present in group five have allotropes. And bismuth does not have allotropy because of its variable oxidation state and it does not have an inert pair effect due to its different oxidation state.Hence, option (B) is correct.
The phosphorus have two common allotropes and that is, white phosphorus and red phosphorus. Hence, option (C) is incorrect.
The arsenic shows three allotropes and that is, yellow, black and grey allotrope. Hence, the option (D) is incorrect.

Hence, option (B) is correct.

Note:
We must have to know that the same chemical element with different structural forms is known as allotropes. And it shows different physical properties like hardness, color and different chemical behaviors. Among the chemical elements, phosphorus has more allotropes (six). And the allotropes have different molecular structure which means they have different chemical activity.