Which of the following molecules contains polar bonds but is nonpolar?

CH2Cl2, F2, H2O, NH3, CCl4

CCl4

Explanation:

In CCl4, there have been 4 symmetric arrangement of bonds around the main (center) carbon atom. Every bond is polar, that you can decide by contrasting carbon's and chlorine's electronegativity. The electronegativity corresponds to how powerfully the electrons bind the molecule. Whenever the two atoms in a covalent bond have opposite electronegativity, they can transfer their electron pair in that bond to one atom, creating a polar bond.

Since the 4 chlorine atoms are symmetrically arranged, the bonds ' polarity cancels each other out, rendering them a non-polar molecule.