Is the CF4 molecule polar or nonpolar ?
The Correct Answer and Explanation is:
The CF₄ molecule is nonpolar.
Carbon tetrafluoride (CF₄) is composed of one carbon atom bonded to four fluorine atoms in a tetrahedral geometry. While the carbon–fluorine bonds themselves are polar due to the significant difference in electronegativity between carbon and fluorine, the overall molecule is nonpolar because of its symmetrical shape.
The carbon atom sits at the center of a tetrahedron with the four fluorine atoms at the corners. In this configuration, the dipole moments of the individual C–F bonds point outward in equal magnitude but in directions that are evenly spaced around the central atom. Due to this perfect symmetry, the bond dipoles cancel each other out, resulting in no net dipole moment for the entire molecule.
Electronegativity is the measure of an atom’s ability to attract electrons. Fluorine is the most electronegative element, which means it pulls electrons more strongly than carbon. Each C–F bond has a dipole moment directed toward the fluorine atom. However, because all four bonds are identical and evenly distributed in three-dimensional space, the individual dipoles counterbalance. This cancellation is a key factor in determining whether a molecule with polar bonds can still be nonpolar overall.
If the geometry of the molecule were different — for example, if one of the fluorine atoms were replaced with a different atom or if there was a lone pair on the central atom — then the symmetry would be broken. This would result in a net dipole moment, making the molecule polar. But in CF₄, the symmetry is intact.
In conclusion, even though the bonds in CF₄ are polar, the molecular geometry causes their dipole effects to cancel out, making the entire molecule nonpolar. This is a classic example in chemistry where molecular shape plays a critical role in determining the polarity of a compound.
