Question

In the PhET simulation window, click the Two Atoms menu in the top left corner of the screen. Click on the partial charges check box to see the partial charges of the atoms. Vary the electronegativity of atom A and atom B and observe the effects on the partial charge of each accordingly. Use the PhET to complete the sentences describing how electronegativity is related to bond dipole experienced by the molecule.

Answer 1

When two atoms with different electronegativities are bonded together, a bond dipole exists. These are displayed with an arrow originating at the atom with the lowest electronegativity and pointing toward the atom with the highest electronegativity.

Partial charges will exist on each atom when a bond exists between two atoms with different electronegativities. Since the atom with a higher electronegativity will have a stronger ability to attract electron, it will have a partial negative charge. The atom with a lower electronegativity will have an equal and opposite positive charge. As the difference in electronegativity increases, the resulting magnitudes of the partial charges will increase.

Bond character is used to describe the severity of the electronegativity differences between the two tans involved in a bond. Bonds that have ionic character correspond to a larger difference in electronegativities and covalent bond character corresponds to a smaller difference.

For example, increasing the electronegativity of an atom A in the PhET simulation and decreasing the electronegativity of atom B will result in a bond that is more ionic in character.