Electron Affinity By: Victoria Geissler, Nichole Hollon, Daniel Rosenberg, and Ben Schlechter

Definition of Electron Affinity Electron Affinity is when the energy is absorbed in the process in which an electron is added to a neutral isolated gaseous atom to form a gaseous ion with a one charge and has a negative value if energy is released. This is kind of like gravity. Electron Affinity is when the energy is absorbed in the process in which an electron is added to a neutral isolated gaseous atom to form a gaseous ion with a one charge and has a negative value if energy is released. This is kind of like gravity.

Concept Electrons as said in the previous slide is the different amounts of energy that is absorbed when an electron is added to an neutral cut off gaseous atom to create a gaseous ion (an ion is an atom or a group of atoms that carries an electric charge) with a charge. In other words the energy is released. Electrons as said in the previous slide is the different amounts of energy that is absorbed when an electron is added to an neutral cut off gaseous atom to create a gaseous ion (an ion is an atom or a group of atoms that carries an electric charge) with a charge. In other words the energy is released.

Electron Configurations This graph shows the behavior of the electron affinity. The shell of the most bound vacancy is indicated by its spectroscopic designation.

Effective Nuclear Charge The effective nuclear charge, Zeff, is the amount of positive charge on the nucleus perceived by an electron. The effective nuclear charge, Zeff, is the amount of positive charge on the nucleus perceived by an electron. Electrons intervening between the nucleus and an outer electron are said to shield or screen the outer electron from the nucleus so that the outer electron does not experience the full nuclear charge. Electrons intervening between the nucleus and an outer electron are said to shield or screen the outer electron from the nucleus so that the outer electron does not experience the full nuclear charge.

Periodic Trends of Electron Affinity The electron affinity is a measure of the energy change when an electron is added to a neutral atom to form a negative ion. For example, when a neutral chlorine atom in the gaseous form picks up an electron to form a Cl- ion, it releases energy of 349 kJ/mol or 3.6 eV/atom. It is said to have an electron affinity of -349 kJ/mol and this large number indicates that it forms a stable negative ion. Small numbers indicate that a less stable negative ion is formed. Groups VIA and VIIA in the periodic table have the largest electron affinities. The electron affinity is a measure of the energy change when an electron is added to a neutral atom to form a negative ion. For example, when a neutral chlorine atom in the gaseous form picks up an electron to form a Cl- ion, it releases energy of 349 kJ/mol or 3.6 eV/atom. It is said to have an electron affinity of -349 kJ/mol and this large number indicates that it forms a stable negative ion. Small numbers indicate that a less stable negative ion is formed. Groups VIA and VIIA in the periodic table have the largest electron affinities.

Periodic Trends Ionization energies are always concerned with the formation of positive ions. Electron affinities are the negative ion equivalent, and their use is almost always confined to elements in groups 6 and 7 of the Periodic Table. Ionization energies are always concerned with the formation of positive ions. Electron affinities are the negative ion equivalent, and their use is almost always confined to elements in groups 6 and 7 of the Periodic Table. In electron affinity the energy is released when a single electron is combined with an isolated atom; its value is determined by the effective charge on the nucleus and the size and electronic configuration of the atom. The energy change accompanying the addition of an electron to a species. The energy given off when a neutral atom in the gas phase picks up an electron to form a negatively charged ion. In electron affinity the energy is released when a single electron is combined with an isolated atom; its value is determined by the effective charge on the nucleus and the size and electronic configuration of the atom. The energy change accompanying the addition of an electron to a species. The energy given off when a neutral atom in the gas phase picks up an electron to form a negatively charged ion.

Bibliography astr.gsu.edu/hbase/chemical/eleaff.html astr.gsu.edu/hbase/chemical/eleaff.html astr.gsu.edu/hbase/chemical/eleaff.html astr.gsu.edu/hbase/chemical/eleaff.html theory/electron-affinity.html theory/electron-affinity.html theory/electron-affinity.html theory/electron-affinity.html affinity affinity affinity affinity zzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_a_ 18zPzhtm zzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_a_ 18zPzhtm zzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_a_ 18zPzhtm zzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_a_ 18zPzhtm xenon.che.ilstu.edu/genchemhelphomepage/glossary/e.html xenon.che.ilstu.edu/genchemhelphomepage/glossary/e.html xenon.che.ilstu.edu/genchemhelphomepage/glossary/e.html en.wikipedia.org/wiki/Electron_affinity en.wikipedia.org/wiki/Electron_affinity en.wikipedia.org/wiki/Electron_affinity