Final answer:
Among the given elements, nitrogen has the highest electronegativity since it is located towards the upper right of the periodic table, which is closer to fluorine, the element with the highest known electronegativity. So the correct option is B.
Step-by-step explanation:
The question asks which of the provided elements has the highest electronegativity: lithium, nitrogen, potassium, arsenic, or beryllium. Electronegativity is a measure of the tendency of an atom to attract electrons. From the information given, we know that electronegativity generally increases diagonally from the lower left to the upper right of the periodic table. Keeping this in mind, among the listed options, nitrogen (B) has the highest electronegativity because it lies closer to fluorine, which is the most electronegative element, on the periodic table. Lithium (A) and potassium (C) are both alkali metals with generally low electronegativities, arsenic (D) has moderate electronegativity, and beryllium (E) has low electronegativity but higher than the alkali metals listed.