Question

which of these covalent bonds is polar, based on the electronegativity of the elements? o - o c - n

Explanation:

Step1: Recall polarity - electronegativity rule

A covalent bond is polar if there is a significant difference in electronegativities of the two atoms.

Step2: Analyze O - O bond

Oxygen atoms in O - O have the same electronegativity (3.44 on the Pauling scale). The electronegativity difference $\Delta\chi=3.44 - 3.44=0$. So, it is non - polar.

Step3: Analyze C - N bond

The electronegativity of carbon (C) is 2.55 and of nitrogen (N) is 3.04. The electronegativity difference $\Delta\chi = 3.04-2.55 = 0.49$. Since $\Delta\chi>0$, the C - N bond is polar.

Answer:

C - N