Question

The most metallic element among the following is:
A. P
B. As
C. Bi
D. Sb

Answer 1

Hint: First of all, to start this question, we need the basic knowledge of the periodic table, especially the arrangement of these given 4 elements in the periodic table.
The periodicity in properties of elements has to be known and especially the electropositive nature trend in periodic table.
The above given elements are from the same group, so thus we should study the group trend of electropositive nature, which will give us a metallic nature trend also.

Complete step by step answer:
We know that the periodic table is divided into 4 blocks known as s-block, p-block, d-block and f-block. Now we also know that there are 18 vertical columns called groups and 7 horizontal rows called periods.
We have to study any periodic property in periods and in groups as well.
To understand the periodic property of metallic and non-metallic nature, we have to understand electropositive nature and electronegative nature.
Generally, we have seen that metals are electron donors, and by giving electrons they show electropositive nature. So, here, we have to compare the electropositive nature of these above 4 elements.
All the above 4 elements belong to group 15 of the periodic table. We know directly the electropositive trend in groups as we go top to bottom is that the electropositive nature will increase. When we arrange these 4 elements from top to bottom so we get the order as: P, As, Sb, Bi.
The last element is Bismuth (Bi), so thus the most metallic element is Bi.

So, the correct answer is Option C.

Additional Information:
We can also study a little deeper according to size variation. Now, we know that the size of the Bismuth atom is largest, as it has maximum shells among all other 3 given elements. So the nucleus has weak hold on external electrons of Bismuth, or in other words, effective nuclear charge is less for Bismuth, and thus Bismuth cannot hold electrons as strongly compared to others, so it can give electrons easily, and the one which gives electron easily is more metallic, thus Bi is most metallic among all others.

Note:
As we already know, the 4 elements belong to group 15, which is in the p block in periodic table. Now among the given 4 elements, Phosphorous (P) is a non-metal, Arsenic (As) and Antimony (Sb) are metalloids, but Bismuth (Bi) has metallic character. Bismuth also has lowest ionization energy and lowest electronegativity among 4 given elements. Thus the most metallic character is of Bi.