Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Input: The principle of equalization of this quantity states that for a chemical compound, this quantity is the geometric mean of that of the compound's constituent elements. That principle was developed by Sanderson, who defined this quantity as an atom's (*) electron density divided by its expected electron density. Mulliken defined this quantity as the arithmetic mean of the first ionization energy and electron affinity. The square root of the ionic resonance energy is the definition of this quantity provided by Linus Pauling. For 10 points, name this ability of an atom to attract electrons to itself in a bond.
Output:
Science