You may be wondering what the difference is between ionization energy energy and electronegativity. Ionization energy is a measurement of energy and can be determined from laboratory experiments. However, electronegativity is not a measurable quantity. Instead, electronegativity values are numbers that are determined mathematically. (The mathematical determination of electronegativity values are derived by using equations relating bond energies developed by Linus Pauling.) The values for electronegativity range from 0.7 to 4.0, where 0.7 represents the value for the least electronegative element (Cs), and 4.0 represents the electronegativity value for the most electronegative element (F). The following table gives the electronegativities for selected elements of the periodic table:
Electronegativity Values for Selected Elements
Here's a "quick trick" to use to determine the relative ionization energies and electronegativities of elements in the periodic table. (For simplicity, we will assume that these trends are the same. Note, however, that there are a few exceptions!) As both ionization energy and electronegativity increase going across a period, and decrease going down a group, fluorine (F, found in the upper right corner of the periodic table) is the element with the largest values for ionization energy and electronegativity. In general, the closer an element is to F in the periodic table, the larger the element's values for ionization energy and electronegativity.
For example, let's compare the ionization energies and electronegativities for bromine (Br) and iodine (I). As bromine is higher in the group than iodine, and hence closer to fluorine, we can conclude that the ionization energy and electronegativity of bromine must be greater than than of iodine. What can you say about the relative ionization energies and electronegativity values for lithium (Li) and sodium (Na)?
Comments
Post a Comment