Answer
Usually elements with 1, 2, or 3 electrons in the outermost shell lose electrons
(a) potassium will lose 1 electron to form a $K^{+}$ cation
(b) sulfur will not lose an electron
(c) fluorine will not lose an electron
(d) barium will lose 2 electrons to form a $Ba^{2+}$ cation
(e) copper will lose 2 electrons to form a $Cu^{2+}$ cation
Work Step by Step
As given above
