Question

For which set of elements, "diagonal relationship" exists?

• A. $B,Si$
• B. $Li,Mg$
• C. $B,Mg$
• D. $Be,Al$

Answer 1

Answer: (A), (B), (D)

The correct options are
A $B,Si$
B $Li,Mg$
D $Be,Al$

A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table . These pairs (lithium $\left(Li\right)$ and megnesium $\left(Mg\right)$, berilium $\left(Be\right)$ and aluminium $\left(Al\right)$, boron $\left(B\right)$ and silicon $\left(Si\right)$ etc.) exhibit similar properties; for example, boron and silicon are both semiconductors, forming halides that are hydrolysed in water and have acidic oxides.
Hence options A,B & D are correct.