Question

What is diagonal relationship? Give two examples to illustrate the concept.

Answer 1

Hint: Boron and Silicon are both semiconductors, forming halides that are hydrolysed in water and have acidic oxides. Diagonal Effects occur when the elements have the tendency to not have characteristics of their own family, but characteristics close to the element that is right one and down one, hence the word is diagonal.

Complete answer:
First, let us see what is a diagonal relationship.
A diagonal relationship in S-block elements exists between adjacent elements which are located in the second and third period of the periodic table. A diagonal relationship mainly occurs between 2nd and 3rd periods of the periodic table. For example, between the elements like, Li and Mg , Be and Al, B and Si.

As we go from left to right in a period table certain properties change in such a way that they neutralize the effect of change in properties on going down the group so as to form a relationship with them that other elements fail to show.

Let us see, why diagonal relationship occurs?
Diagonal relationship occurs because of the different ways in which many atomic properties vary down groups and across the periodic table.

Let us understand better with an example!
Lithium of group 1A and second period shows similarities with the properties of magnesium which are located in the 2nd group and 3rd period.
Similarly, Properties of beryllium which are located in the third period and third group. The two elements which show similarities in their properties can be called a diagonal pair.

Note: The diagonal relationship is due to the polarizing power, that is ionic radius being similar for the diagonally placed elements. Basically diagonal relationship is due to the similarity in ionic sizes of the element.