Final answer:
K (potassium) and Cl (chlorine) are most likely to form an ionic bond, producing potassium chloride (KCl). The other element pairs listed are more likely to form covalent bonds rather than ionic bonds.
Step-by-step explanation:
The elements most likely to form an ionic bond are K (potassium) and Cl (chlorine). Within this pair, potassium (K), being a metal with a low electronegativity, will tend to lose one electron to become a K+ ion, while chlorine (Cl), a non-metal with a high electronegativity, will gain an electron to become a Cl- ion. Therefore, K and Cl form an ionic compound, known as potassium chloride (KCl).
Looking at the rest of the options, S and Cl (option b) are both non-metals and more likely to form a covalent bond due to their similar electronegativities. K and Ca (option c) are both metals and do not typically form ionic bonds with each other. C and O (option d) would form a covalent bond, as they are both non-metals with comparable electronegativities.
For other examples mentioned:
- For S (sulfur) and Cl (chlorine), one would predict a definitely polar covalent bond.
- For P (phosphorus) and O (oxygen), the bond would also be covalent, and likely polar due to differences in electronegativity.
- For Cs (cesium) and O (oxygen), the bond would be ionic, given cesium's low electronegativity and tendency to lose electrons while oxygen tends to gain electrons.