Which compound most likely contains polar covalent bonds?

• A. H2O
• B. O2
• C. CH4
• D. NaCl

Answer: (A)

Verified step by step guidance

1. Understand the concept of polar covalent bonds: These occur when two atoms share electrons unequally due to a difference in electronegativity. The atom with higher electronegativity attracts the shared electrons more strongly, creating a partial negative charge, while the other atom becomes partially positive.
2. Identify the electronegativity values of the elements involved: Oxygen (O) has a high electronegativity, while hydrogen (H) has a lower electronegativity. This difference suggests that the bond between O and H in H2O is polar covalent.
3. Analyze each compound: H2O consists of hydrogen and oxygen, which have a significant difference in electronegativity, leading to polar covalent bonds. O2 consists of two oxygen atoms with equal electronegativity, resulting in nonpolar covalent bonds. CH4 consists of carbon and hydrogen, which have a small difference in electronegativity, leading to nonpolar covalent bonds. NaCl consists of sodium and chlorine, which have a large difference in electronegativity, resulting in ionic bonds.
4. Compare the compounds: Among the given options, H2O is the compound where the difference in electronegativity between the bonded atoms (O and H) is significant enough to create polar covalent bonds.
5. Conclude that H2O is the compound most likely to contain polar covalent bonds due to the significant difference in electronegativity between oxygen and hydrogen.