Lithium shows diagonal relationship with Magnesium.
- Due to its small size lithium differs from other alkali metals but resembles magnesium, as its size is closer to lithium.
- Diagonal relationship is formed due to the identical size of ions.
- As we move downward across a group in the periodic table then the size of the atoms gradually increases.
- As we move towards right across a period in the periodic table, then the size of the atom reduces.
- A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods (first 20 elements) of the periodic table.