You are absolutely right to think that chlorine is highly electronegative, which would usually lead to polar bonds. However, CCl4 (carbon tetrachloride) is a nonpolar molecule due to its symmetrical tetrahedral geometry.

Here's why:

1. Electronegativity Difference: Chlorine is much more electronegative than carbon. This means the electrons in the C-Cl bonds are pulled closer to the chlorine atoms, creating polar bonds.

2. Molecular Geometry: The four C-Cl bonds in CCl4 are arranged in a tetrahedral shape. This symmetrical arrangement means the individual bond dipoles (the polar bonds) cancel each other out.

3. Net Dipole Moment: Since the individual bond dipoles cancel, the molecule has a net dipole moment of zero, making it nonpolar.

Think of it like this: Imagine you have four people pulling equally on a rope from each direction. They all apply force, but the rope doesn't move because the forces cancel out. The same principle applies to the bond dipoles in CCl4.

Key takeaway: Even though a molecule contains polar bonds, its overall polarity depends on its molecular geometry. If the geometry is symmetrical, the polar bonds can cancel out, resulting in a nonpolar molecule.