Elements that readily lose electrons are all metals. Metals that normally lose one electron all form +1 ions with electron configurations we call “stable,” or “energetically favorable.” Element that are metal tend to loss electrons and became positively charged Ion called cations.
an atom with a single electron in its outermost shell
Explanation:
The electron in the outermost shell of an atom has weakest bonding with the nucleus due to the relatively far distance. Since the lower attraction force can be exerted by nucleus, the single election residing in the outermost shell tends to lose and the atom become an positive charges ion.
One example of atom with single electron in its outermost shell is sodium, Na. Sodium atom can lose its single outermost shell an become positive ion Na+
