Final answer:
2) A nonpolar molecule will not have a dipole because it either has no polar bonds or has polar bonds that are arranged in a symmetrical fashion, making their effects cancel each other out.
Step-by-step explanation:
The molecule that will not have a dipole is a 2) nonpolar molecule.
Polar molecules have an asymmetrical charge distribution, meaning there is an uneven distribution of electrons across the molecule, which leads to a net dipole moment.
In contrast, a nonpolar molecule either has no polar bonds or has polar bonds that are arranged symmetrically, such as in linear or tetrahedral molecular shapes, causing the bond dipoles to cancel each other out.
This results in no overall dipole in the molecule.
Examples of nonpolar molecules include diatomic oxygen (O2) and carbon dioxide (CO2).
In carbon dioxide, the molecule is linear with two oxygen atoms at the ends each forming polar bonds with carbon, but due to the symmetry, the dipoles cancel each other out, leaving CO2 nonpolar.
A molecule with symmetrical charge distribution, like that of methane (CH4), will also not have a dipole as the symmetry allows for the even distribution of charge.