what are the reasons for diagonal relationships?

 

Dear user,

A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table.

Such a relationship occurs because moving left to right and descending top to bottom in the periodic table have opposing effects.

For example, on moving from left to right across a period, there is an increase in electronegativity while, moving down in the group there is a decrease in electronegativity. Therefore, on moving diagonally, the two opposing tendencies almost cancel out and the electronegativity values remain almost same. Thus diagonal pairs have many similar properties.

So, it can be concluded that the similarity of properties such as electronegativity, ionization energy, size etc. between the diagonal elements is the cause of diagonal relationship.

Hope, this helps.

Best wishes!!