The elements belonging to Group 1 and group 2 of periodic table has the strong tendency to form cations.
The reason behind this tendency is that the elements belonging to group 1 and 2 have one and two valance electrons respectively. By loosing the valence electrons, they will aquire noble gas configuration.
It is easy to release 1 and 2 electrons from the outer shell , resulting in the formation of cations.
Electropositivity of these elements is also very high as they readily loose electrons and form the cations.
Below are the elements belonging to the given groups.
Group 1 elements :- Lithium, Sodium, Potassium, Rubidium, Caesium and Francium.
Group 2 elements :- Beryllium , Magnesium, Calcium , Strontium, Barium and Radium.
Caesium is the most electropositive element.