Elements in group 2 are called alkaline earth metals, the most similarity about the alkaline metals is which chemical properties they have.
Further Explanation
Periodic table
Periodic table is a table that contains elements arranged in columns called groups and rows called periods.
Elements are arranged based on physical and chemical properties such that elements in the same group will have similar physical and chemical properties.
Chemical families
Based on the chemical properties elements belong to a family of elements sharing similar chemical or physical characteristics.
Examples of common chemical families include; alkali metals, alkaline-earth metals, halogens and noble gases among others.
Alkaline-earth metals
These are elements that are found in group 2 of the periodic table. Alkaline-earth metals include, Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium.
Properties of Alkaline-earth metals
Alkaline earth metals have a valence of two since they form ions by losing two electrons from their outermost energy levels.
Unlike the Alkali metals, the earth metals have a smaller atom size and are not as reactive compared to alkali metals.
Alkaline-earth metals are highly metallic and are good conductors of electricity.
They react with water and steam to form metal hydroxide and metal oxides respectively
They react with air to form metal oxides
Reactivity of alkaline metals depends on the ease of losing electrons, thus the reactivity increases down the group as the number of energy levels increases.
Additionally, alkaline-earth metals have low electronegativities and low electron affinities