Covalent or Ionic?

Groups 1 and 2 are all metals. So they are likely to form ionic bonds. (Ionic bonds are a metal + a nonmetal.) Group 17 is all nonmetals. So they would form ionic bonds with metals and covalent bonds with other nonmetals. Groups 14, 15 and 16 are more tricky, because they are a mixture of nonmetals, metals and metalloids. So in those groups, the answer is "it depends". If we're talking about Carbon (a nonmetal) in Group 14, then it usually forms covalent bonds. But if we're talking about Lead (a metal or transition metal, depending on how your text breaks the categories up) in Group 14, then it usually forms ionic bonds. See if your textbook has a periodic table that divides the elements into metals, nonmetals and metalloids, and that will make it easier for you to answer this question.