Beryllium shows diagonal relationship with:
A. B
B. Mg
C. Al
D. Na

Answer Verified Verified
Hint: Diagonal relationship is a property that occurs between certain pairs of the elements present diagonally in the second period and third period in the periodic table. These pairs of elements show similar properties. For example, boron and silicon both are semiconductors in nature.

Complete step by step answer:
- We know that periodic contains four blocks, s, p d, and f blocks.
- In those blocks only few elements show the property of diagonal relationship.
- The below image shows which elements show the diagonal relationship.

- From the above image we can say that lithium and magnesium show diagonal relationship.
- In the question it is asked that Beryllium shows diagonal relationship with which metal.
- By seeing the above image we can easily say that beryllium is in diagonal relationship with aluminum.
So, the correct option is C.

Additional information:
Both the metals (beryllium and aluminum) have an affinity to form covalent compounds. For example the chlorides of both the elements being covalent and are soluble in organic solvents.
Beryllium and aluminum have the same electronegativity and the polarizing power ratio of their ions is similar.
Both \[BeC{{l}_{2}}\] and \[AlC{{l}_{3}}\] act as Lewis acids.
Both the metals dissolve in strong alkalies (like NaOH) to form soluble complexes.
The oxides of both the metals Be (BeO) and Al (\[A{{l}_{2}}{{O}_{3}}\]) are hard, high melting point and are insoluble solids.
Carbides of Beryllium and aluminum metals react with water and liberate methane gas a product.

Note: Beryllium belongs to the 2A (s block element) group and Aluminum belongs to the 3A (p block element) group. The diagonal relation is not going to depend on which block they belong to. It is going to depend on the properties that the elements exhibit.