Coulombs Law describes the interaction between two charges and varies by the magnitude of these charges and inversely with the distance between them. For atoms, we'll label the charges as the nuclear charge and electron charge. 9192 9nuclelec As you go up in atomic number (Z), the number of protons in the nucleus increases, making the charge on the nucleus increase, so that in general. qnuc = Z ·(+1) However if we think only of the electrons in the outermost shells (valence electrons), they do not see the full strength of the nuclear charge because it is partially shielded (or canceled out if you prefer) by the core electrons. So we define something called effective charge. Shielding Experiences net charge of about 1+ Nucleus Effective Charge = # of protons Zeff = Z – core # of core electrons In general, Zeff increases as you go across in the periodic table. 1. Fill out the following table to verify that effective charge increases as you go across a row. Element Na Mg Al Si P S CI Ar Protons 11 Core e 10 Zeff +1 2. For which element in the above table will the coulomb interaction between nucleus and valence electrons be the strongest? The weakest?

Coulombs Law describes the interaction between two charges and varies by the magnitude of these charges and inversely with the distance between them. For atoms, we'll label the charges as the nuclear charge and electron charge. 9192 9nuclelec As you go up in atomic number (Z), the number of protons in the nucleus increases, making the charge on the nucleus increase, so that in general. qnuc = Z ·(+1) However if we think only of the electrons in the outermost shells (valence electrons), they do not see the full strength of the nuclear charge because it is partially shielded (or canceled out if you prefer) by the core electrons. So we define something called effective charge. Shielding Experiences net charge of about 1+ Nucleus Effective Charge = # of protons Zeff = Z – core # of core electrons In general, Zeff increases as you go across in the periodic table. 1. Fill out the following table to verify that effective charge increases as you go across a row. Element Na Mg Al Si P S CI Ar Protons 11 Core e 10 Zeff +1 2. For which element in the above table will the coulomb interaction between nucleus and valence electrons be the strongest? The weakest?

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter7: Molecular Structures

Section: Chapter Questions

Problem 58QRT

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