To illustrate, an atom of an alkali metal (group 1) loses one electron and forms a cation with a 1+ charge; an alkaline earth metal (group 2) loses two electrons and forms a cation with a 2+ charge, and so on. For example, a neutral calcium atom, with 20 protons and 20 electrons, readily loses two electrons.
Explanation: As you know, neutral atoms become ions by losing or by gaining electrons. ... In this case, elements located in group 2 will always lose electrons to become cations. More specifically, they will always lose 2 electrons to form 2+ cations.