Question

The element which has the strongest metallic bond among $ _{11}{A^{23}} $ , $ _{12}{B^{24}} $ $ _{13}{C^{27}} $ and $ _{19}{D^{39}} $ is:
a) A
b) B
c) C
d) D

Answer 1

Hint: The chemical bond that came from the electrostatic energy between electrons of metals is known as the metallic bond. It is the bond where the free electrons lie in the sea of positively charged ions.

Complete step by step solution:
A metal is defined as the substance which is hard, lustrous, ductile, and has very good electrical and thermal conductivity. For example- iron, gold, silver.
A metallic bond can be termed as the chemical bond that came from the electrostatic energy between electrons of metals. It is the bond where the free electrons lie in the sea of positively charged ions.
In the periodic table the elements on the left hand side are called as metals mostly and on moving from left side to right side the metallic nature decreases. The elements on the right hand side are often known as nonmetals and metalloids. But on moving down the group the metallic nature increases.
The metallic bonding of an element depends upon the number of unpaired electrons present in the outermost shell of the element.
As the number of unpaired electrons increases, the metallic bond becomes stronger and more strong.
So according to question,
 $ _{11}{A^{23}} $ Has one outermost electron, as $ 1{s^2}2{s^2}2{p^6}3{s^1} $ . Thus it has one unpaired electron and will show very low ionization energy.
 $ _{12}{B^{24}} $ Has two electron in the outermost shell, as $ 1{s^2}2{s^2}2{p^6}3{s^2} $ . Thus it has two unpaired electrons and will have low ionization energy.
 $ _{13}{C^{27}} $ Has three electron in the outermost shell, as $ 1{s^2}2{s^2}2{p^6}3{s^2}3{p^1} $ . Thus it has three unpaired electrons. So the energy to pull the electron will be higher and thus the metallic bond formed will be strongest among all.
 $ _{19}{D^{39}} $ Has one outermost electron, as $ 1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}4{s^1} $ . Thus it has one unpaired electron and will show low ionization energy.
Hence the correct option is (c).

Note:
Generally the electronic configuration $ 1{s^2}2{s^2}2{p^6}3{s^2}3{p^1} $ lies in the p-block elements. This is the electronic configuration of the Aluminium which is the second member of group $ 13 $ elements. Aluminium exists in a stable $ + 3 $ oxidation state. Hence it always forms trivalent compounds.