Sorry if you picked fluorine. Fluorine is a nonmetal in group 7A. It has a very high ionization energy and high electron affinity. This results from the small atomic radius for fluorine. Fluorine typically reacts to gain an electron. Fluorine never loses an electron in chemical reactions.

Great, if you picked calcium.  Calcium is a metal in group 2A.

It has eighteen inner electrons and two outer or valence electrons in a 4s subshell. These two electrons can be removed relatively easily. They are far away from the plus charge on the nucleus. Calcium forms a cation with a charge of +2 just like Mg, Be, Sr, Ba in the alkaline earths.