For ten points, name this quantity for which Pauling arbitrarily set fluorine equal to 4.
Most famously measured by the Pauling scale, it is defined as the "power of an atom when in a molecule to attract electrons to itself".  In practice it is used to find which molecule will be a better electron donor, or whether ionic or covalent bonds will form.  For ten points, name this quantity for which Pauling arbitrarily set fluorine equal to 4.
Most famously measured by the Pauling scale, it is defined as the "power of an atom when in a molecule to attract electrons to itself".  
electronegativity