The molecule that has a non-polar covalent bond is

Step 1: Analyze the question We need the molecule whose covalent bond is non-polar, meaning the electrons are shared equally between the bonded atoms.

Step 2: The concept Bond polarity depends on the difference in electronegativity between the bonded atoms:

• Different atoms (different electronegativities) give unequal sharing, so the bond is polar covalent. The more electronegative atom gets a partial negative charge (δ−).
• Identical atoms (same electronegativity) give equal sharing, so the bond is non-polar covalent.

Step 3: Check each option

| Option | Bond | Electronegativity difference | Type | |---|---|---|---| | A. HCl | H–Cl | Cl (3.0) vs H (2.1), about 0.9 | Polar | | B. NH₃ | N–H | N (3.0) vs H (2.1), about 0.9 | Polar | | C. Cl₂ | Cl–Cl | 0 (same atom) | Non-polar | | D. H₂O | O–H | O (3.5) vs H (2.1), about 1.4 | Polar |

In Cl₂, both chlorine atoms pull on the shared pair of electrons with exactly the same strength. The electrons are shared equally, so there is no partial charge on either atom.

Step 4: Answer The molecule with a non-polar covalent bond is Cl₂, which is option C.

Exam tip: Look for diatomic molecules made of one element (H₂, O₂, N₂, Cl₂, F₂, Br₂, I₂). They always have non-polar covalent bonds because the two atoms are identical. If the atoms in the bond are different, the bond is almost always polar.