Carbon dioxide (CO2) itself does not have a single electronegativity value because it is a molecule made up of two different elements: carbon and oxygen. However, we can look at the electronegativity values of the individual elements.
Electronegativity, a concept developed by Linus Pauling, is a measure of an atom’s ability to attract and hold onto electrons when it is part of a compound. In the Pauling scale, carbon has an electronegativity of approximately 2.5, while oxygen is more electronegative, with a value of about 3.5. This difference leads to a polar covalent bond between the carbon and oxygen atoms in CO2.
When considering CO2 as a whole, it is important to note that the molecule is linear and symmetrical. This symmetry results in the individual dipole moments canceling each other out, making CO2 a nonpolar molecule overall, despite the polar bonds between C and O. Thus, while CO2 displays polarity due to the electronegativity difference, its molecular geometry leads to a nonpolar characterization.