which of the following molecules has at least one polar bond?\na carbon dioxide - co₂\nb oxygen - o₂\nc…

which of the following molecules has at least one polar bond?\na carbon dioxide - co₂\nb oxygen - o₂\nc nitrogen - n₂\nd none of the above
Answer
Explanation:
Step1: Recall polar - bond concept
A polar bond forms between atoms with different electronegativities.
Step2: Analyze $O_2$
In $O_2$, two oxygen atoms have the same electronegativity. So, the $O - O$ bond is non - polar.
Step3: Analyze $N_2$
In $N_2$, two nitrogen atoms have the same electronegativity. So, the $N - N$ bond is non - polar.
Step4: Analyze $CO_2$
In $CO_2$, the $C=O$ bonds are between carbon (electronegativity = 2.5) and oxygen (electronegativity = 3.5). There is an electronegativity difference, so the $C=O$ bonds are polar.
Answer:
A. carbon dioxide - $CO_2$