A polar covalent bond would form in which one of the following pairs of atoms?

• A. Na and Cl
• B. O and O
• C. H and Cl
• D. C and C

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the concept of bond polarity. A polar covalent bond forms when two atoms share electrons unequally due to a difference in their electronegativities.
2. Step 2: Recall that electronegativity is a measure of an atom's ability to attract shared electrons in a bond. The greater the difference in electronegativity between two atoms, the more polar the bond.
3. Step 3: Analyze each pair of atoms by comparing their electronegativities: For example, Na and Cl have a large difference, but they typically form an ionic bond rather than a covalent bond.
4. Step 4: Consider O and O or C and C pairs, where the atoms are identical, so the electronegativity difference is zero, resulting in a nonpolar covalent bond.
5. Step 5: For H and Cl, the electronegativity difference is moderate, leading to unequal sharing of electrons and thus forming a polar covalent bond.