Final answer:
Electronegativity is a measure of the ability of an atom to attract electrons in a compound. C) Electronegativity values generally increase from left to right across the periodic table.
Step-by-step explanation:
Electronegativity is a measure of the ability of an atom to attract electrons when the atom is part of a compound. Electronegativity values generally increase from left to right across the periodic table. Therefore, option C is correct.
Option A is incorrect because electronegativity is not a measure of the attraction of an electron by an isolated atom, but rather by an atom in a compound. Option B is incorrect because elements with a high electronegativity can form both ionic and covalent compounds.
Option D is incorrect because electronegativity values are not used to calculate the dipole moment of an atom. Option E is incorrect because it makes a generalization that all metals form only covalent compounds, which is not true.