Final answer:
If atoms have similar electronegativities, the resulting covalent bond is considered nonpolar. Electronegativity is key in determining bond polarity; equal or nearly equal electronegativities mean an equal sharing of electrons and a nonpolar bond.
Step-by-step explanation:
If atoms have similar electronegativities, bonds containing them are also considered nonpolar. Covalent bonds form between atoms when they share electrons to fill their valence electron shells. A nonpolar covalent bond forms between two atoms of the same element or between different elements that share electrons equally. For example, molecular oxygen (O₂) is nonpolar because the electrons will be equally distributed between the two oxygen atoms.
The polarity of a covalent bond is determined by the property of electronegativity, which is a measure of the tendency of an atom to attract electrons towards itself. When atoms in a bond have identical or very close electronegativity values, the shared electrons are distributed equally, resulting in a nonpolar bond. Conversely, when there is a significant difference in electronegativity between the atoms, the shared electrons are drawn more towards the more electronegative atom, leading to a polar bond.