Electronegativity difference is plotted against the average value of this quantity for a crystal in Mooser-Pearson diagrams. This quantity is used to help categorize the K, L, and M edges that are produced during X-ray adsorption spectroscopy. (-5[1])Ionization energy is proportional to the squared ratio of effective nuclear charge and this quantity. (-5[1])The difference in (-5[1])the reciprocals of the squares of two values of this quantity is related (-5[1])to the emitted (*) wavelength by the hydrogen-specific Rydberg formula. Electron transitions to a region where this quantity is 1 and 2 are used to define the Lyman and Balmer series, respectively. This integer quantity is used to identify which energy shell a bound electron is likely occupying. For 10 points, the letter (10[1])n symbolizes the what first of four quantum numbers? ■END■ (10[2]0[1])