Final answer:
The compound that contains polar covalent bonds but is overall nonpolar is CF4, due to its symmetrical tetrahedral shape that causes the individual dipole moments to cancel out.
Step-by-step explanation:
The question is asking to choose a compound that contains at least one polar covalent bond but is overall nonpolar. A polar covalent bond occurs when the electronegativity difference between the two atoms involved in the bond is between 0.5 and 2.0, leading to an unequal distribution of electron density. However, a nonpolar molecule exists when the overall shape of the molecule distributes the electron density symmetrically, even if it contains polar bonds.
The correct answer is d. CF4. Carbon tetrafluoride (CF4) has polar covalent bonds due to the difference in electronegativity between carbon (2.5) and fluorine (4.0). However, the molecule's symmetrical tetrahedral geometry ensures the individual bond moments cancel each other out, making the molecule nonpolar as a whole. Other options either form polar molecules due to their shape (HCN, ICl3) or, such as SeBr4, are not commonly discussed in the context of high school chemistry, hence it can't be definitively categorized without further context.