Final answer:
Option A is incorrect because polar covalent bonds do not occur between atoms of the same element; they form between atoms of different elements with varying electronegativities, resulting in an unequal sharing of electrons.
Step-by-step explanation:
To answer the question regarding which of the following is not true of polar covalent bonds: A. Polar covalent bonds exist between atoms of the same element. B. Polar covalent bonds create two poles across the bond. C. Polar covalent bonds result from the unequal sharing of electrons. D. Electronegativity differences for atoms with polar covalent bonds range between 0.5 and 2.0, option A is not true.
Polar covalent bonds occur between two atoms of different elements with an electronegativity difference that results in an unequal sharing of electrons. This difference typically ranges between 0.5 and 2.0, depending on the sources, which indicates a degree of polarity. For example, water molecules are held together by polar covalent bonds, which give it its unique characteristics due to the slightly positive and slightly negative charges that develop on different ends of the bond.
Meanwhile, nonpolar covalent bonds form between atoms that share electrons equally, which can include atoms of the same element, as in O₂. Since polar covalent bonds are defined by the unequal sharing of electrons between different elements and because nonpolar covalent bonds can occur between atoms of the same element with equal sharing, the statement in option A is incorrect.