Which among the following elements shows a diagonal relationship with Beryllium?
A) B
B) Mg
C) Al
D) Ne

Hint: Elements that are present in the second and third period of the periodic table are said to possess a particular relationship between the elements which are arranged diagonally with each other. These diagonally arranged elements i.e. two elements placed diagonally from left to right in two adjacent periods and two adjacent groups are known to exhibit some similar chemical and physical properties.

Complete Step by Step Solution:
As we have already mentioned, the first element of a particular group shows similarities in properties with the second element of the next diagonal group. This is called the diagonal relationship between these two elements. Be and Al show a diagonal relationship with each other as these elements are present diagonally in the periodic table and have the following chemical and physical similarities:
- Both form halides like \[BeC{l_2}\] and \[AlC{l_3}\] which act as Lewis acids.
- Al has an electronegativity of about 1.61 and Be has an electronegativity of 1.58 which are nearly the same.
- Both elements prefer to form covalent compounds.
Therefore, the correct answer to this question will be, option (C).

Note: The diagonal elements show a lot of similarities. This particular relationship is exhibited as we move from the left to the right of the period and down the group in the periodic table. The periodic table has quite a few opposing factors. These relationships occur due to the various ways in which many atomic properties vary down the groups and across periods of the Periodic Table. Along with the group and periodic relationships, the elements of s and p-block elements also exhibit diagonal relationships.