Ionization+Energies

The amount of energy needed to remove an electron. As we travel across the periodic table (left to right) the amount of energy required to remove an electron increases. There is a higher core charge as we go to the right, therefore the electrons are more strongly held by the nucleus. As we travel down the periodic table, the amount of energy required to remove an electron decreases. The greater number of layers cause the valence electrons to be further away from the nucleus making them susceptible for removal.
 * What is it?**
 * The Elements**

There are many different grades of ionization energy. First ionization energy, second ionization energy, and third ionization energy are the most common. First ionization energy (I1) is the energy needed to remove the first electron from a neutral atom, an example of this would be K+(g) + e- ---> K(g). Second ionization energy (I2) is defined as being the energy needed to remove the second electron from a neutral atom, an example of this would be K+2 + e- ---> K+. The Third ionization energy (I3) is the energy needed to remove the third ionization energy from an atom, an example of this would be Sc +3 + e- ---> Sc +2. Each number of ionization energies increases similarly; however, the greater the ionization energy, the more difficult it is to remove an electron.

This picture illustrates the ionization energy in the periodic table.
 * [|www.shodor.org/.../ students/background.html]**