After an atom has lost an electron it becomes a/an and has a charge.

ion positive An atom normally has exactly as many electrons as protons, and has 0 overall charge. And a charged atom is called an ion. An ion may have either a positive or negative charge depending upon if it has fewer electrons than protons, or more electrons than protons. Since in this case, it lost an electron, that means that there's more protons than electrons, so the atom has a positive charge since protons have a positive charge.