Here's why:

* Polar molecules have an uneven distribution of electrons, resulting in a partial positive charge on one end of the molecule and a partial negative charge on the other end. This creates a dipole moment.

* Nonpolar molecules have an even distribution of electrons. The electrons are shared equally between the atoms, resulting in no separation of charge.

Here are some key characteristics of nonpolar molecules:

* Symmetrical shape: Nonpolar molecules often have a symmetrical shape, which contributes to the even distribution of electrons.

* Similar electronegativity: The atoms in a nonpolar molecule have similar electronegativity values, meaning they share electrons equally.

* Weak intermolecular forces: Nonpolar molecules have weaker intermolecular forces (like London dispersion forces) compared to polar molecules, which have stronger forces like dipole-dipole interactions and hydrogen bonding.

Examples of nonpolar molecules:

* CO2 (Carbon dioxide)

* CH4 (Methane)

* O2 (Oxygen)

* N2 (Nitrogen)

* H2 (Hydrogen)