Here's a breakdown:

* Covalent bonds involve the sharing of electrons between atoms.

* Nonpolar covalent bonds occur when the electrons are shared equally between the two atoms. This happens when the atoms have the same electronegativity, meaning they have an equal pull on the shared electrons.

Examples of nonpolar covalent bonds:

* H-H (Hydrogen gas): Both hydrogen atoms have the same electronegativity.

* Cl-Cl (Chlorine gas): Both chlorine atoms have the same electronegativity.

* O=O (Oxygen gas): Both oxygen atoms have the same electronegativity.

Key points:

* Nonpolar covalent bonds are symmetrical.

* The difference in electronegativity between the atoms is zero.

* Molecules with only nonpolar covalent bonds are nonpolar molecules.

Let me know if you have any more questions!