Question

What is the difference in electronegativity in a C−C bond? What type of bond is it?

Answer 1

The difference in the electronegativity leads to a bond polarity. Bond polarity is the separation of electric charges along a bond, which leads to a molecule having a dipole moment. Polarity will generate if the atoms across a bond will have different electronegativities

Complete answer:
A bond is said to be polar if there is electronegativity difference between the atoms across the bond. The electrons are not always equally shared in a bond. The atom with more electronegativity will have a partial negative charge. Because of this it will pull the electron cloud closer to itself. The less electronegative atom will generate a partial positive charge. This unequal sharing of electrons will lead to the bond polarity and thus generation of electric dipole.
The bond given to us is $C - C$ .Both the atoms across the bond are the same. The electronegativity of Carbon is 2.55. The difference in the electronegativity is $\Delta E = 2.55 - 2.55 = 0$
Hence the bond is nonpolar. The bond can be named as Covalent Nonpolar Bond. If the difference in the electronegativity is between 0-0.4 then the bond is non-Polar.
Therefore, the difference in electronegativity is Zero and the bond is Covalent Non-Polar Bond.

Note:
Consider the C-H bond. The electronegativity of Hydrogen is 2.1. The difference in E.N is < 0.4, hence this is also a Nonpolar bond. N-H, O-H, H-F have high electronegativity differences and are highly polar. The bonds formed by the atoms like N , O come under this category.