Chapter 18.2, Problem 12R

To determine

To choose: two elements that are likely to form an ionic bond and covalent bond out of the element O, Ne, S, Ca, and K.

To explain: the reason behind the formation of an ionic and covalent bond.

Explanation of Solution

Introduction:

Ionic bonds are formed by the complete exchange of valence electrons between the atoms. On the other hand, a covalent bond involves the sharing of electrons in the outermost shell between the atoms.

An ionic bond is formed by gaining or losing electrons. A bond formed by the sharing of electrons is called a covalent bond. Calcium (C) belongs to group 2 and potassium (K) belongs to group 1. So, calcium has 2 electrons in its outermost shell and potassium (K) has 1 electron in its outermost shell. Calcium and potassium lose their outermost shell electrons and develop the charge over themselves. Therefore, calcium (C) and potassium (K) both are ions that are used to form the ionic bond.

Oxygen (O) and sulfur (S) both belong to group 16. O and S both have six electrons in their outermost shell and they need 2 more electrons to attain a noble gas configuration. Thus, both of them are used to form a covalent bond.

Conclusion:

Hence, Ca, K forms an ionic bond, and S, O form a covalent bond.