 |
Following is a
series of terms and concepts that relate to the Properties of
Atoms as determined by Electronic Configurations. |
| |
Following is a
series of terms and concepts that relate to the Properties of
Atoms as determined by Electronic Configurations. |
| An Anion is an atom or group of atoms that contains more electrons than protons. Because of the imbalance of charge the system will have a net charge that is negative. Consequently, any negatively charged system is referred to as an anion. The term is pronounced as if it were two words, an ion. |
 |
The Atomic Radius is a very common method of measuring the relative sizes of atoms. It is determined as half the distance between two identical atoms when bonded together. For instance, half the distance between two atoms of Oxygen in O2 will be the atomic radius of an Oxygen atom. |
| A Cation is an atom or group of atoms that contains more protons than electrons. Because of the imbalance of charge the system will have a net charge that is positive. Consequently, any positively charged system is referred to as a cation. The term is pronounced as if it were two words, cat ion. |
|
Electron Affinity is a measure of the desire or ability of an atom to gain electrons. It is an energy concept. The formal definition states that Electron Affinity is the amount of energy released when an electron as added to an atom. Most atoms tend to lose energy when they gain electrons. Some atoms do not. Those that do not tend to appear in the lower left corner of the Periodic Chart. The concept of Electron Affinity tends to be viewed as an exothermic process. The elements located in the upper right corner of the Periodic Chart have the high E.A. values while those in the lower left corner have the low E.A. values. This is interpreted as meaning that elements in the upper right corner are usually found an anions while those in the lower left corner are usually not found as anions. A generic equation of the E.A. process would be as follows.  |
|
The concept of Electronegativity refers to the ability of a bonded atom to pull electrons towards itself.
 There are many different methods available for assigning electronegativity values. Of all the options available, the most widely used set of values was determined by Pauling and is called the Pauling Scale. It assigns the largest electronegativity value to Fluorine and lowest to Francium. Fluorine has an electronegativity of 4.0, and Francium has an electronegativity of 0.7. The numbers are unitless because they are ratios. |
|
Ionization Potential is an energy term. It refers to the process of cation formation. The definition states that Ionization Potential is the amount of energy required to remove the highest energy electron from the valence level of an atom. Because energy must be put into the system, the process in endothermic. Consequently, from an energy point of view, this is an unfavorable process. Atoms in the upper right hand corner of the Periodic Chart have the largest I.P. values and the elements in the lower left corner of the Periodic Chart have the lowest I.P. values. Because the elements in the lower left corner need the smaller amounts of energy to form cations, these elements are usually found as cations in chemical process. The elements in the upper right corner, on the other hand, need larger amounts of energy to form cations. Therefore, they are not usually going to appear as cations. The generic equation of the Ionization Potential process is as follows.  There are additional Ionization Potential terms, such as 2nd I.P., 3rd I.P., and so on. This refers to the sequential removal of electrons from an atom. There will be one I.P. value for each electron that at system has. |
| Questions and comments should be sent to : | kdrews@bcpl.net |  |