Question

For each of the following pairs of elements, predict whether they will form a bond that is primarily ionic or one that is primarily covalent. Explain your answers.
lithium (Li) and oxygen (O) chlorine (Cl) and fluorine (F) calcium (Ca) and sulfur (S)

Answer 1

Types of Bonds can be predicted by calculating the difference in electronegativity.
If, Electronegativity difference is,

                 Less than 0.4 then it is Non Polar Covalent

                 Between 0.4 and 1.7 then it is Polar Covalent

                 Greater than 1.7 then it is Ionic 

For Li and O,

                    E.N of Oxygen                 =   3.44

                    E.N of Lithium                  =   0.98
                                                             ________

                      E.N Difference                     2.46          (Ionic Bond)

For Cl and F,
                    E.N of Fluorine                 =   3.98

                    E.N of Chlorine                 =   3.16
                                                             ________

                      E.N Difference                     0.82   (Mildly Polar Covalent Bond)

For Ca and S,
                    E.N of Sulfur                   =   2.58

                    E.N of Calcium                =   1.00
                                                             ________

                      E.N Difference                   1.58          (Polar Covalent Bond)