The tendency of an element to lose electrons and forms positive ions (cations) is called electropositive or metallic character. The elements having lower ionisation energies have higher tendency to lose electrons, thus they are electropositive or metallic in their behaviour.
Alkali metals are the most highly electropositive elements.
Periodicity:
In period- The electropositive or metallic characters decreases from left to right in a period.
In group- The electropositive or metallic characters increases from top to bottom in a group.
