What is the main similarity among elements in group 2?

Chemical Properties

Explanation:

Elements belonging to same group in a periodic table have same chemical properties. This similarity in chemical properties arises mainly from the same number of valence shell electrons. Group 2 elements also called Alkaline Earth Metals have two valence electrons in their valence shell with following electronic configuration ...

ns²

Where "n" represents principle quantum number or number of main shell.

The reactivity of these elements is due to the metallic behavior as these elements looses two electrons to form a cation with + 2 oxidation number. i. e.

X → X⁺² + 2 e⁻

Therefore, all elements present on Group II will form a cation with + 2 oxidation number and behave in the same manner with different reagents.