* Polar Covalent Bonds: These bonds form when electrons are shared *unequally* between two atoms. This happens because one atom has a stronger pull on the electrons (higher electronegativity). This creates a slightly positive charge on one atom and a slightly negative charge on the other, resulting in a dipole moment.
* Non-Polar Covalent Bonds: These bonds form when electrons are shared *equally* between two atoms. This happens when the two atoms have identical or very similar electronegativities. There is no separation of charge and no dipole moment.
Key Takeaway: The very definition of a covalent bond implies the sharing of electrons. If the sharing is *not* equal, it becomes a polar covalent bond. Therefore, a bond cannot be both non-polar and covalent.
What might be the confusion?
You might be thinking about something like a non-polar molecule. A molecule can be non-polar even if it has polar covalent bonds within it, if the polarities cancel each other out due to the molecule's shape (like CO2).
