October+1st+Chem.+Skits


 * Electron Affinities**


 * Definition:** The amount of energy released when a neutral atom gains an electron.

Ionization energy is is the amount of energy required to remove the highest energy electron (in the valence shell) from an isolated neutral atom in the gaseous state. Ionization energy increases as it goes up the periodic table and to the right. Ionization is an endothermic process. The atom/molecule increases in energy as electrons are removed, and each subsequent electron requires more energy to be removed. When removing from an s orbital significantly more energy is needed to remove an electron than is is from a p orbital, except when moving up to a stable p orbital. An example is Aluminum. The electron configuration in the valence shell is 3s2 3p1. Removing the first electron requires a certain amount of energy. The following electron would be removed from a full s shell, so it needs quite a bit for energy. Then the third ionization energy would take the electron in 3s12-. The fourth ionization energy shows a huge jump from 3 to 4 because the fourth electron is being removed from the 2s2, 2p6 shell.
 * Ionization Energy**

Effective Nuclear Charge is the charge an electron experiences after accounting for the shielding of the in between electrons. The periodic trends of the Effective Nuclear Charge INCREASE as going across the periodic table; and DECREASE as going DOWN the periodic table.
 * Effective Nulear Charge**

Symbols: Zeff Z= number of protons S= number of electrons Formula: Zeff=Z-S

Zeff = Z – shielding by other electrons


 * Electronegativities**
 * an atom's ability to attract bonding electrons to itself
 * electrons tend to go to the more electronegative atoms because there is more pull from the nucleus
 * electrons are taken from the d orbital first, then the p orbital and lastly the s orbital, bcause the electrons in the d orbital are farthest from the nucleus
 * If A - B = 0 - 0.7 the bond is covalent
 * if A - B = 0.7 - 1.7 the bond is polar
 * if A - B = 1.7 - 3.3 the bond is ionic
 * On the periodic table, electronegativity increases toward the right of the table, and increases toward the top (Fluorine is the most electronegative element)