Which of the following elements forms the most polar covalent bond with hydrogen?

• A. Fluorine (F)
• B. Carbon (C)
• C. Nitrogen (N)
• D. Oxygen (O)

Answer: (A)

Verified step by step guidance

1. Understand that the polarity of a covalent bond depends on the difference in electronegativity between the two atoms involved. The greater the difference, the more polar the bond.
2. Recall the electronegativity values of the elements involved: Hydrogen (H) has an electronegativity of about 2.1, Carbon (C) about 2.5, Nitrogen (N) about 3.0, Oxygen (O) about 3.5, and Fluorine (F) about 4.0 on the Pauling scale.
3. Calculate the electronegativity difference for each bond with hydrogen: For example, for Fluorine-H bond, the difference is |4.0 - 2.1| = 1.9, and similarly for the others.
4. Compare these differences: the bond with the largest electronegativity difference will be the most polar covalent bond.
5. Conclude that since Fluorine has the highest electronegativity difference with hydrogen, the H-F bond is the most polar covalent bond among the options.