Consider the following element combinations. Classify the bonds formed between each pair as ionic, polar covalent, or nonpolar covalent qualitatively based solely on each element's position on the periodic table? Do not conduct calculations.

Jun 24, 2017

color(red)("Rb" + "I": ionic
color(blue)("Br" + "Br": nonpolar covalent
color(green)("S" + "I": polar covalent
color(blue)("N" + "N": nonpolar covalent
color(green)("O" + "F": polar covalent
color(red)("Cs" + "Cl": ionic
color(red)("Ca" + "O": ionic
color(green)("P" + "I": polar covalent

Explanation:

Something worth knowing about deciding between nonpolar and polar is that only two of the same element can form an ideally nonpolar bond.

With this in mind, the $\text{Br"-"Br}$ and $\text{N"-"N}$ are both nonpolar covalent bonds.

Bonds between a metal and a nonmetal are almost always considered "ionic", so the $\text{Rb"-"I}$, $\text{Cs"-"Cl}$, and $\text{Ca"-"O}$ are all ionic bonds.

And therefore, the remaining binary compounds ($\text{S"-"I}$, $\text{O"-"F}$, and $\text{P"-"I}$), which are those with two nonmetals, form polar covalent bonds, those in which electrons are dispersed unevenly throughout the bond.

In summary,

color(red)("Rb" + "I": ionic
color(blue)("Br" + "Br": nonpolar covalent
color(green)("S" + "I": polar covalent
color(blue)("N" + "N": nonpolar covalent
color(green)("O" + "F": polar covalent
color(red)("Cs" + "Cl": ionic
color(red)("Ca" + "O": ionic
color(green)("P" + "I": polar covalent