Summary of Trends in the Periodic Table PDF

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Personal notes summarizing trends in the periodic table...

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Summary of Trends in the Periodic Table Below is a summary of factors that affect periodic trends or the electrostatic force.  These factors really affect only one “thing” about the electrons in an atom, which is the electrostatic force on an electron (how hard electrons are being held onto). Factor 1: Orbit number, n  Comparing elements above and below on the periodic table  As n increases, the valence electrons are further from the nucleus Factor 2: Nuclear charge (number of protons), Z  Comparing elements left and right on the periodic table  As Z increases (and the orbit number remains the same), there is a stronger electrostatic force Trends 1.

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Atomic radius: The atomic radius is defined as one-half the distance between the nuclei of identical atoms that are bonded together. Ionic Radius: The ionic radius is the distance between the nucleus and the electron in the outermost shell of an ion. Ionization Energy: The minimum energy required to remove an electron from an atom or ion in the gas phase. Metallic Character: Refers to the level of reactivity of a metal. Metallic bonding accounts for many physical properties of metals, such as strength, malleability, ductility, thermal and electrical conductivity, opacity, and luster. Electron Affinity: The electron affinity of an atom or molecule is defined as the amount of energy released when an electron is attached to a neutral atom or molecule in the gaseous state to form a negative ion. The energy released when an atom gains one electron. Non-metallic Character: Relates to the tendency to accept electrons during chemical reactions. Electronegativity: A measure of the tendency of an atom to attract a bonding pair of electrons. It is not an actually physical property that can be measured – it has been determined/”made up” by scientists. As you move down the periodic table:  Atomic radius increases  Ionization energy decreases  Metallic character increases  Electron affinity decreases  Non-metallic character decreases

As you move right across the periodic table:     

Atomic radius decreases Ionization energy increases Metallic character decreases Electron affinity increases Non-metallic character increases...