Chemistry - A Molecular Science

(Nora) #1

Chapter 3 Atomic Structure and Properties


Atomic radii Ionization energy Electronegativity
largest

small

larger

larger

higher low higher low

highest higher highest higher

Figure 3.9 Periodic trends in the labeled properties Arrows indicate direction in the periodic table of increasing atomic radii, ionization energy, and electronegativity.


so nonmetals have high electronegativities b


ecause they have high effective nuclear


charges. The trends in atomic size, ionization energies, and electronegativities are summarized in Figure 3.9. Paramagnetic atom


s are attracted by magnetic fields because


they have unpaired electrons. In contrast, di


amagnetic atoms are not attracted by magnetic


fields because all of their electrons are paired.



  1. define electronegativity and pr


edict trends in it from the per

iodic table (Section 3.6); and


  1. define ionization energy and predict trends in


it from the periodic table (Section 3.5);


  1. determine the number of valence electrons present in an atom (Section 3.1);
    After studying the material presented in this chapter, you should be able to:

  2. predict whether an atom is parama


gnetic or diamagnetic (Section 3.7).


  1. predict trends in atomic radii fr


om the periodic table (Section 3.3);


  1. predict relative valence orbita


l energies of atoms (Section 3.4)


  1. distinguish between valence and core electrons (Section 3.1); 3. predict valence electron co4. explain shielding and effective nuclear charge (Section 3.2);


nfigurations (Section 3.1);

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