Question

Identify the elements in the Periodic Table:

A: Which shows diagonal relationship to $Be$

B: Which shows diagonal relationship to $Li$

• A. $A:Al,B:Mg$
• B. $A:Si,B:Mg$
• C. $A:Mg,B:Al$
• D. $A:Al,B:Si$

Answer 1

The correct option is A $A:Al,B:Mg$

In addition to horizontal and vertical trends, there is a diagonal relationship between elements such as $Li$ and $Mg$, $Be$ and $Al,B$ and $Si$, that have an adjacent upper left/lower right relative location in the periodic table.
These pairs of elements have similar size and electronegativity, resulting in similar properties.